ci: disable GitHub Actions on forks

.github/workflows/main.yml

@@ -14,6 +14,7 @@ jobs:
   tests:
     name: Run tests
     runs-on: ${{ matrix.os }}
+    if: github.repository == 'ohmyzsh/ohmyzsh'
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]

.github/workflows/project.yml

@@ -9,6 +9,7 @@ jobs:
   add-to-project:
     name: Add to project
     runs-on: ubuntu-latest
+    if: github.repository == 'ohmyzsh/ohmyzsh'
     env:
       GITHUB_TOKEN: ${{ secrets.PROJECT_TOKEN }}
     steps: