Merge pull request #305 from mwclient/dependabot/github_actions/actions/checkout-4

Bump actions/checkout from 3 to 4

.github/workflows/tox.yml

@@ -24,7 +24,7 @@ jobs:
             python-version: "3.6"
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - name: Set up Python ${{ matrix.python-version }}