Upgrade GitHub Actions (kkroening#643)

Author: cclauss

.github/workflows/ci.yml

@@ -17,9 +17,9 @@ jobs:
           - "3.9"
           - "3.10"
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v3
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install ffmpeg