Update .github/workflows/ci.yml

Author: hattya

.github/workflows/ci.yml

@@ -51,7 +51,9 @@ jobs:
           vim_version: ${{ matrix.vim_version }}
           download: ${{ matrix.download }}
       - name: Setup Python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.x
       - name: Install covimerage
         run: |
           python -m pip install -U pip setuptools wheel