build(ci): bump zig to 0.15.1 and add more platforms

- Bump zig version to 0.15.1 and workaround zig fetch hang (ziglang/zig#24916)
- add mac os zig build (currently without luajit, linker failure)
- Add windows zig build, currently with very limited testing

.github/workflows/test.yml

@@ -204,7 +204,8 @@ jobs:
         name: Show logs
         run: cat $(find "$LOG_DIR" -type f)
 
-  zig-build:
+  # TODO: matrixify
+  zig-build-linux:
     runs-on: ubuntu-24.04
     timeout-minutes: 45
     name: build using zig build (linux)
@@ -212,8 +213,15 @@ jobs:
       - uses: actions/checkout@v5
       - uses: mlugg/setup-zig@v2
         with:
-         version: 0.14.1
+          version: 0.15.1
       - run: sudo apt-get install -y inotify-tools
+
+      # This is a workaround for "zig fetch" being unable to decompress lua-dev-deps.tar.gz
+      # As the hash in build.zig.zon is calculated after decompression, we can preload the cache instead.
+      # This is hopefully fixed for zig 0.15.2, see https://github.com/ziglang/zig/issues/24916
+      - run: curl -L https://github.com/neovim/deps/raw/06ef2b58b0876f8de1a3f5a710473dcd7afff251/opt/lua-dev-deps.tar.gz | zcat > lua-dev-deps.tar
+      - run: zig fetch lua-dev-deps.tar
+
       - run: zig build test_nlua0
       - run: zig build nvim && ./zig-out/bin/nvim --version
       - run: zig build unittest
@@ -223,6 +231,42 @@ jobs:
       - run: cd runtime; ../zig-out/bin/nvim -u NONE -i NONE -e --headless -c "helptags ++t doc" -c quit
       - run: diff -u runtime/doc/tags zig-out/runtime/doc/tags
 
+  zig-build-macos-15:
+    runs-on: macos-15
+    timeout-minutes: 45
+    name: build using zig build (macos 15)
+    steps:
+      - uses: actions/checkout@v4
+      - uses: mlugg/setup-zig@v2
+        with:
+          version: 0.15.1
+
+      - run: curl -L https://github.com/neovim/deps/raw/06ef2b58b0876f8de1a3f5a710473dcd7afff251/opt/lua-dev-deps.tar.gz | zcat > lua-dev-deps.tar
+      - run: zig fetch lua-dev-deps.tar
+
+      - run: zig build test_nlua0 -Dluajit=false
+      - run: zig build nvim_bin -Dluajit=false && ./zig-out/bin/nvim --version
+      - run: zig build functionaltest -Dluajit=false
+
+  zig-build-windows:
+    runs-on: windows-2022
+    timeout-minutes: 45
+    name: build using zig build (windows)
+    steps:
+      - uses: actions/checkout@v4
+      - uses: mlugg/setup-zig@v2
+        with:
+          version: 0.15.1
+
+      - run: curl -L https://github.com/neovim/deps/raw/06ef2b58b0876f8de1a3f5a710473dcd7afff251/opt/lua-dev-deps.tar.gz -O
+      - run: 7z x lua-dev-deps.tar.gz
+      - run: zig fetch lua-dev-deps.tar
+      - run: zig build test_nlua0
+      - run: zig build nvim_bin
+      - run: ./zig-out/bin/nvim --version
+      # TODO: support entire test suite
+      - run: zig build functionaltest -- test/functional/api/buffer_spec.lua
+
   windows:
     uses: ./.github/workflows/test_windows.yml