ci: Add a skips job where we can accumulate skip conditions (#10901)

This adds a new job that we can use to set outputs to accumulate skip
conditions for other tests. The major change here is skipping all tests
if we're only updating vouches, to save our CI.

I also included a number of minor skips based on filepaths.

.github/workflows/test.yml

@@ -11,26 +11,71 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  paths:
+  # Determines whether other jobs should be skipped. Modify this if there
+  # are other fast skip conditions, and add it as an output. Then modify
+  # other tests `needs/if` to check them. Document the outputs.
+  skip:
     if: github.repository == 'ghostty-org/ghostty'
     runs-on: namespace-profile-ghostty-xsm
     outputs:
+      # 'true' when all changed files are non-code (e.g. only VOUCHED.td),
+      # signaling that all other jobs can be skipped entirely.
+      skip: ${{ steps.determine.outputs.skip }}
+      # Path-based filters to gate specific linter/formatter jobs.
+      actions_pins: ${{ steps.filter.outputs.actions_pins }}
+      blueprints: ${{ steps.filter.outputs.blueprints }}
       macos: ${{ steps.filter.outputs.macos }}
+      nix: ${{ steps.filter.outputs.nix }}
+      shell: ${{ steps.filter.outputs.shell }}
+      zig: ${{ steps.filter.outputs.zig }}
+
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - uses: dorny/paths-filter@de90cc6fb38fc0963ad72b210f1f284cd68cea36 # v3.0.2
         id: filter
         with:
           filters: |
+            code:
+              - '**'
+              - '!.github/VOUCHED.td'
             macos:
               - '.swiftlint.yml'
               - 'macos/**'
+            actions_pins:
+              - '.github/workflows/**'
+              - '.github/pinact.yml'
+            shell:
+              - '**/*.sh'
+              - '**/*.bash'
+            nix:
+              - 'nix/**'
+              - '*.nix'
+              - 'flake.nix'
+              - 'flake.lock'
+              - 'default.nix'
+              - 'shell.nix'
+            zig:
+              - '**/*.zig'
+              - 'build.zig*'
+            blueprints:
+              - 'src/apprt/gtk/**/*.blp'
+              - 'nix/build-support/check-blueprints.sh'
+
+      - id: determine
+        name: Determine skip
+        run: |
+          if [ "${{ steps.filter.outputs.code }}" = "false" ]; then
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "skip=false" >> "$GITHUB_OUTPUT"
+          fi
 
   required:
     name: "Required Checks: Test"
+    if: always()
     runs-on: namespace-profile-ghostty-xsm
     needs:
-      - paths
+      - skip
       - build-bench
       - build-dist
       - build-examples
@@ -633,7 +678,8 @@ jobs:
         run: Get-Content -Path ".\build.log"
 
   test:
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-md
     outputs:
       zig_version: ${{ steps.zig.outputs.version }}
@@ -828,7 +874,7 @@ jobs:
       fail-fast: false
       matrix:
         i18n: ["true", "false"]
-    name: Build -Di18n=${{ matrix.simd }}
+    name: Build -Di18n=${{ matrix.i18n }}
     runs-on: namespace-profile-ghostty-sm
     needs: test
     env:
@@ -859,7 +905,8 @@ jobs:
           nix develop -c zig build -Di18n=${{ matrix.i18n }}
 
   zig-fmt:
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true' && needs.skip.outputs.zig == 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-xsm
     timeout-minutes: 60
     env:
@@ -887,7 +934,8 @@ jobs:
 
   pinact:
     name: "GitHub Actions Pins"
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true' && needs.skip.outputs.actions_pins == 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-xsm
     timeout-minutes: 60
     permissions:
@@ -918,7 +966,8 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
   prettier:
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-xsm
     timeout-minutes: 60
     env:
@@ -945,9 +994,9 @@ jobs:
         run: nix develop -c prettier --check .
 
   swiftlint:
-    if: github.repository == 'ghostty-org/ghostty' && needs.paths.outputs.macos == 'true'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true' && needs.skip.outputs.macos == 'true'
     runs-on: namespace-profile-ghostty-macos-tahoe
-    needs: paths
+    needs: skip
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -967,7 +1016,8 @@ jobs:
         run: nix develop -c swiftlint lint --strict
 
   alejandra:
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true' && needs.skip.outputs.nix == 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-xsm
     timeout-minutes: 60
     env:
@@ -994,7 +1044,8 @@ jobs:
         run: nix develop -c alejandra --check .
 
   typos:
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-xsm
     timeout-minutes: 60
     env:
@@ -1021,7 +1072,8 @@ jobs:
         run: nix develop -c typos
 
   shellcheck:
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true' && needs.skip.outputs.shell == 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-xsm
     timeout-minutes: 60
     env:
@@ -1053,7 +1105,8 @@ jobs:
             $(find . \( -name "*.sh" -o -name "*.bash" \) -type f ! -path "./zig-out/*" ! -path "./macos/build/*" ! -path "./.git/*" | sort)
 
   translations:
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-xsm
     timeout-minutes: 60
     env:
@@ -1080,7 +1133,8 @@ jobs:
         run: nix develop -c .github/scripts/check-translations.sh
 
   blueprint-compiler:
-    if: github.repository == 'ghostty-org/ghostty'
+    if: github.repository == 'ghostty-org/ghostty' && needs.skip.outputs.skip != 'true' && needs.skip.outputs.blueprints == 'true'
+    needs: skip
     runs-on: namespace-profile-ghostty-xsm
     timeout-minutes: 60
     env: