Revert: "chore(deps): Bump aws-actions/stale-issue-cleanup from 5 to …

…6" (aws#23197)

This broke again... [There is no v6](https://github.com/aws-actions/stale-issue-cleanup) 😕 

Reverts aws#23111

Created PR aws#23199 to prevent dependabot from attempting to update to v6 again

.github/workflows/close-stale-issues.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     name: Stale issue job
     steps:
-    - uses: aws-actions/stale-issue-cleanup@v6
+    - uses: aws-actions/stale-issue-cleanup@v5
       with:
         # Setting messages to an empty string will cause the automation to skip
         # that category