Run browserstack not every time, for real

Author: adriaandotcom

.github/workflows/testing.yml

@@ -66,7 +66,7 @@ jobs:
   browserstack:
     runs-on: ubuntu-latest
     needs: unit-tests
-    if: github.event_name == 'push' || github.event_name == 'workflow_dispatch'
+    if: (github.event_name == 'push' && github.ref == 'refs/heads/main') || github.event_name == 'workflow_dispatch'
 
     strategy:
       matrix: