Basic cache provider never caches the configuration cache

Hi, and thanks for setup-gradle.

With cache-provider: basic, the configuration cache never survives between jobs. On a fresh GitHub-hosted runner with the basic cache restored, a build with org.gradle.configuration-cache=true still logs:

Calculating task graph as no cached configuration is available for tasks: build

From the code this looks expected: both restore() and save() derive their paths from getCachePaths(), which only covers Gradle User Home:

https://github.com/gradle/actions/blob/9c971963bec38e04b3d30dcc455b5382be2fdbfb/sources/src/cache-service-basic.ts#L156-L158

function getCachePaths(gradleUserHome: string): string[] {
    return [path.join(gradleUserHome, 'caches'), path.join(gradleUserHome, 'wrapper')]
}

The Basic Caching docs describe the same two directories. The configuration cache, though, lives in the project cache directory — <checkout>/.gradle/configuration-cache (Gradle 9.7.1). I verified it on a runner: the entry directories (<hash>, <uuid>) appear under .gradle/configuration-cache/, while find ~/.gradle -iname '*configuration-cache*' finds nothing.

Since every hosted job starts from a fresh checkout, the entry can never be restored: ~/.gradle/caches (including build-cache-1) is shared, but configuration isn't — even when consecutive jobs run the exact same command on the same commit. We know --project-cache-dir can relocate the project cache dir into Gradle User Home as a workaround, but it's surprising to have to configure that in every workflow.

So, two questions:

1. Is this by design — i.e. the basic provider intentionally keeping project-scoped state out of scope for it? In general, are there reasons why one wouldn't want to restore the Gradle configuration cache?
2. If not, could the action start caching .gradle/configuration-cache in the basic provider's cached paths?

If you don't want to go for it, a documented limitation in the Basic Caching section would also be fine.

Happy to test a change or open the PR if you're interested.

Start in sources/src/cache-service-basic.ts at getCachePaths(), then trace how restore() and save() consume its paths. Check the Basic Caching section in docs/setup-gradle.md and verify whether adding the project configuration-cache path is appropriate; done means the configuration cache survives between jobs or the limitation is documented.