Use self-hosted as tmp workaround for broken prod deploys (#23183)

Author: rsese

.github/workflows/prod-build-deploy.yml

@@ -21,7 +21,7 @@ concurrency:
 jobs:
   build-and-deploy:
     if: ${{ github.repository == 'github/docs-internal'}}
-    runs-on: ubuntu-latest
+    runs-on: ${{ fromJSON('["ubuntu-latest", "self-hosted"]')[github.repository == 'github/docs-internal'] }}
     timeout-minutes: 15
     steps:
       - name: Check out repo