fix: quote python 3.10 in CI

Author: ziirish

.github/workflows/test.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.7, 3.8, 3.9, 3.10, pypy3]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "pypy3"]
     steps:
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v1
@@ -40,7 +40,7 @@ jobs:
       - name: Set up Python 3.8
         uses: actions/setup-python@v1
         with:
-          python-version: 3.8
+          python-version: "3.8"
       - name: Checkout ${{ github.base_ref }}
         uses: actions/checkout@v2
         with: