Merge pull request #5471 from mathstuf/actions-only-on-main-repo

ci: only run `lock` and `regress` workflows on the main repo

.github/workflows/lock.yml

@@ -16,6 +16,7 @@ concurrency:
 jobs:
   action:
     runs-on: ubuntu-latest
+    if: github.repository == 'tmux/tmux'
     steps:
       - uses: dessant/lock-threads@v6
         with:

.github/workflows/regress.yml

@@ -16,6 +16,7 @@ jobs:
   regress:
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.runner }}
+    if: github.repository == 'tmux/tmux'
     timeout-minutes: 45
 
     strategy: