Revert "Run cloud tests if secrets are available"

This reverts commit aa648bdcac.

.github/workflows/tests.yml

@@ -170,8 +170,9 @@ jobs:
           echo $RESTIC_TEST_GS_APPLICATION_CREDENTIALS_B64 | base64 -d > $GOOGLE_APPLICATION_CREDENTIALS
           go test -cover -parallel 4 ./internal/backend/...
 
-        # only run cloud backend tests if secrets are available (pushes and pull requests for our own repo)
-        if: secrets && matrix.test_cloud_backends
+        # only run cloud backend tests for pull requests from our own repo,
+        # otherwise the secrets are not available
+        if: github.event.pull_request.head.repo.full_name == github.repository && matrix.test_cloud_backends
 
       - name: Check changelog files with calens
         run: |