Get rid of version warning in CI

Author: goggle

.github/workflows/addoncheck-matrix.yml

@@ -11,6 +11,8 @@ jobs:
     - uses: actions/checkout@v3
     - name: Set up Python
       uses: actions/setup-python@v4
+      with:
+        python-version: '3.x'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip

.github/workflows/addoncheck-nexus.yml

@@ -11,6 +11,8 @@ jobs:
     - uses: actions/checkout@v3
     - name: Set up Python
       uses: actions/setup-python@v4
+      with:
+        python-version: '3.x'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip

.github/workflows/flake8.yml

@@ -11,6 +11,8 @@ jobs:
     - uses: actions/checkout@v3
     - name: Set up Python
       uses: actions/setup-python@v4
+      with:
+        python-version: '3.x'
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip