Update actions/setup-python action to v4

Author: renovate-bot

.github/workflows/gh-page.yml

@@ -18,7 +18,7 @@ jobs:
           fetch-depth: 0
 
       - name: Set up Python 3.6
-        uses: actions/setup-python@v3.1.2
+        uses: actions/setup-python@v4.0.0
         with:
           python-version: 3.6
 

.github/workflows/lint.yml

@@ -15,7 +15,7 @@ jobs:
     steps:
       - uses: actions/[email protected]
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v3.1.2
+        uses: actions/setup-python@v4.0.0
         with:
           python-version: ${{ matrix.python-version }}
       - uses: actions/[email protected]

.github/workflows/test.yml

@@ -52,7 +52,7 @@ jobs:
     steps:
     - uses: actions/[email protected]
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v3.1.2
+      uses: actions/setup-python@v4.0.0
       with:
         python-version: ${{ matrix.python-version }}