Update release workflow actions to latest versions

This is to avoid "Node.js 12 actions are deprecated" notices.

Author: dairiki

.github/workflows/release.yml

@@ -11,9 +11,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: '3.x'
       - name: Install dependencies