ci: update global workflows (#1106)

.github/workflows/automerge.yml

@@ -49,7 +49,7 @@ jobs:
 
     steps:
       - name: Automerging
-        uses: pascalgn/automerge-action@v0.15.5
+        uses: pascalgn/automerge-action@v0.15.6
         env:
           BASE_BRANCHES: nightly
           GITHUB_TOKEN: ${{ secrets.GH_BOT_TOKEN }}

.github/workflows/issues-stale.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Stale
-        uses: actions/stale@v7
+        uses: actions/stale@v8
         with:
           close-issue-message: >
             This issue was closed because it has been stalled for 10 days with no activity.
@@ -40,7 +40,7 @@ jobs:
           repo-token: ${{ secrets.GH_BOT_TOKEN }}
 
       - name: Invalid Template
-        uses: actions/stale@v7
+        uses: actions/stale@v8
         with:
           close-issue-message: >
             This issue was closed because the the template was not completed after 5 days.