Update python-test.yml

Author: shenxianpeng

.github/workflows/python-test.yml

@@ -51,6 +51,11 @@ jobs:
         runner: [ ubuntu-latest, macos-latest, windows-latest ]
     runs-on: ${{ matrix.runner }}
     steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python 3.10
+      uses: actions/setup-python@v3
+      with:
+        python-version: "3.10"
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip