Bump default milestone to 26.0

Author: ahmedhamidawan

.github/workflows/maintenance_bot.yaml

@@ -12,7 +12,7 @@ jobs:
       pull-requests: write
     runs-on: ubuntu-latest
     env:
-      MILESTONE_NUMBER: 31
+      MILESTONE_NUMBER: 32
     steps:
       - name: Get latest pull request labels
         id: get_pr_labels