Bump actions

(for the last time! moving to `stable` branch vs release tags)

.github/workflows/deep-classifier-monitor.yml

@@ -11,7 +11,7 @@ jobs:
         uses: actions/checkout@v2
         with:
           repository: "microsoft/vscode-github-triage-actions"
-          ref: v42
+          ref: stable
           path: ./actions
       - name: Install Actions
         run: npm install --production --prefix ./actions