Undo commenting. (#7708)

This should have been reverted in a previous PR.

Author: ryanwilson

.github/workflows/spm.yml

@@ -29,8 +29,7 @@ jobs:
 
   cron-only:
     # Don't run on private repo.
-    # REVERT ME:
-    #    if: github.event_name == 'schedule' && github.repository == 'Firebase/firebase-ios-sdk'
+    if: github.event_name == 'schedule' && github.repository == 'Firebase/firebase-ios-sdk'
 
     runs-on: macOS-latest
     strategy: