Update e2e-tests.yml

Author: staabm

.github/workflows/e2e-tests.yml

@@ -383,6 +383,7 @@ jobs:
               ../../bin/phpstan analyze test.php --level=0
             os: "ubuntu-latest"
           - script: |
+              brew install gpatch
               cd e2e/bug-12972
               ../../bin/phpstan analyze
             os: "macos-latest"