Checkout full history for spotless

The spotless action requires enough git history to correctly
determine which files have been modified. This commit configures the
checkout action to fetch the full history by setting
`fetch-depth: 0`.
If we remove usage of ratchetFrom we should be able to remove this.

Author: cartland

.github/workflows/build-sample.yml

@@ -36,6 +36,9 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          # https://github.com/diffplug/spotless/issues/710
+          fetch-depth: 0
 
       - name: Copy CI gradle.properties
         run: mkdir -p ~/.gradle ; cp .github/ci-gradle.properties ~/.gradle/gradle.properties