Update linter.yml

Author: narendasan

.github/workflows/linter.yml

@@ -25,10 +25,10 @@ jobs:
       - uses: actions/checkout@v2
         with:
           ref: ${{ github.event.pull_request.head.sha }}
-      - name: Set up Python 3.9.4
-        uses: actions/setup-python@v2
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v3
         with:
-          python-version: 3.9.4
+          python-version: '3.9'
       - name: Setup env
         run: |
           sudo ln -s $GITHUB_EVENT_PATH /GITHUB_EVENT.json