* docs(README): Create Polaris-Core README (apache#2585)

* docs(README): Create Polaris-Core README

* Add Events for Iceberg REST APIs (apache#2480)

* Update dependency com.google.guava:guava to v33.5.0-jre (apache#2601)

* Bump: Iceberg client in tests and documentation to 1.10 (apache#2588)

* Add client build to Gradle (apache#2590)

* Add client build to Gradle

* Add overwrite option for python build

* Match client build behavior

* Add content to contributing guidelines. (apache#2536)

Add community guidelines.

* CI/Caching: Fix Gradle cache retention (apache#2604)

Older versions of Gradle's setup-gradle action did not actively trigger stale cache entry cleanup, which is why there was a separate step "Trigger Gradle home cleanup" in `gradle.yml`.
Nowadays, that action triggers a "noop build" to explicitly trigger stale cache entry cleanup, but uses somewhat different defaults than [described here](https://docs.gradle.org/current/userguide/directory_layout.html#dir:gradle_user_home:configure_cache_cleanup).

This change adds an explicit configuration for Gradle cache cleanup/retention with reasonable values considering the total 10GB limit for all GitHub caches per repository.

The change described above lead to a behavioral change, which evicts all non-accessed cache entries within the current GH workflow job, which effectively evicted all cache entries from dependent jobs - in other words: the (build) cache was nearly empty, leading to full rebuilds.
This behavior could be observed in the output of the "Post Collect partial Gradle build caches"-step in the log message "Build cache (/home/runner/.gradle/caches/build-cache-1) removing files not accessed on or after ..." showing the timestamp when the setup-gradle action was started.

* Last merged commit d8602f6

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Co-authored-by: Adam Christian <[email protected]>
Co-authored-by: Adnan Hemani <[email protected]>
Co-authored-by: Mend Renovate <[email protected]>
Co-authored-by: Prashant Singh <[email protected]>
Co-authored-by: Yong Zheng <[email protected]>
Co-authored-by: JB Onofré <[email protected]>