chore(deps): update actions/checkout action to v4 (gitbugactions#152)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/lint.yml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3.6.0
+        uses: actions/checkout@v4.1.7
 
       - name: Run linter
         uses: psf/black@stable

.github/workflows/tests.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v3.6.0
+      uses: actions/checkout@v4.1.7
 
     - name: Set up Python
       uses: actions/[email protected]