run upstream dev ci only in main repo (#169)

Author: mathause

.github/workflows/upstream-dev-ci.yaml

@@ -24,7 +24,7 @@ jobs:
     permissions:
       issues: write
     if: |
-        always()
+        github.repository == 'mpytools/mplotutils'
         && (
             github.event_name == 'schedule'
             || contains( github.event.pull_request.labels.*.name, 'run-upstream')