chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/build.yaml

@@ -53,7 +53,7 @@ jobs:
         runs-on: ubuntu-latest
         steps:
             - name: Checkout repo
-              uses: actions/checkout@v4
+              uses: actions/checkout@v6
             - name: Validate domains
               run: |
                   validate_domain() {