Don't run upgrade-patch jobs on forks (#12206)

With the current github-workflow setup, workflows are triggered on every
forked repository (which is quite wasteful).

Add a condition to only run on the main repository.

.github/workflows/upgrade-patch-versions-schedule.yml

@@ -8,6 +8,7 @@ on:
 permissions: {}
 jobs:
   get-releases-branches:
+    if: github.repository == 'kubernetes-sigs/kubespray'
     runs-on: ubuntu-latest
     outputs:
       branches: ${{ steps.get-branches.outputs.data }}