chore: Enable manual triggering for stale issue workflows on Python Agentplatform Repo

PiperOrigin-RevId: 932670039

Author: matthew29tang

.github/workflows/google-contributor-stale.yml

@@ -4,6 +4,7 @@ name: Close inactive google-contributor PRs
 on:
   schedule:
     - cron: "30 2 * * *"
+  workflow_dispatch: {}
 
 jobs:
   stale:

.github/workflows/stale.yml

@@ -3,12 +3,12 @@ name: Mark and close stale issues
 
 on:
   schedule:
-  # Scheduled to run at 1:30 UTC everyday
-  - cron: '30 1 * * *'
+    # Scheduled to run at 1:30 UTC everyday
+    - cron: '30 1 * * *'
+  workflow_dispatch: {}
 
 jobs:
   stale:
-
     runs-on: ubuntu-latest
     permissions:
       issues: write