fix: upgrade pip before running tox

.github/workflows/tests.yml

@@ -79,27 +79,37 @@ jobs:
     steps:
       - name: Set Newline Behavior
         run : git config --global core.autocrlf false
+
       - uses: actions/checkout@v3
         with:
           fetch-depth: 0
+
       - name: Set up Python
         uses: actions/setup-python@v3
         with:
           python-version: ${{ matrix['python-version'] }}
+
+      - name: Upgrade pip
+        run: python -m pip install --upgrade pip
+
       - name: Install tox
         run: python -m pip install --upgrade tox
+
       - name: Get Tox Environment Name From Matrix Name
         uses: rishabhgupta/split-by@v1
         id: split-matrix-name
         with:
           string: '${{ matrix.name }}'
           split-by: '-'
+
       - name: Test with coverage
         if: "! contains(matrix.name, 'pypy3')"
         run: python -m tox -e ${{ steps.split-matrix-name.outputs._0}}-cov
+
       - name: Test without coverage
         if: "contains(matrix.name, 'pypy3')"
         run: python -m tox -e ${{ steps.split-matrix-name.outputs._0}}
+
        # TODO: https://github.com/pytest-dev/pytest-html/issues/481
 #      - name: Upload coverage to codecov
 #        if: github.event.schedule == ''