Update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/semver.yaml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         fetch-depth: '0'
     - name: Bump version and push tag