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

Author: renovate[bot]

.github/workflows/validate.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: tests
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Download code coverage results
       uses: actions/download-artifact@v4
       with: