1. Enables gradle task caching. This seems to be possible because of the pegasus and gradle version upgrades ( https://github.com/linkedin/rest.li/commits/master/gradle-plugins/src/main/java/com/linkedin/pegasus/gradle/PegasusPlugin.java and linkedin/rest.li@7cfe8bf), even though it wasn't previously possible (4a77576)
2. Use https://github.com/gradle/gradle-build-action in github actions to cache gradle dependencies. Not sure how much this will help, but it's worth a shot. We might need to audit our task dependencies and things to make sure the cache doesn't cause problems when working across machines.

For debugging the cache, we also now get nice reports as part of the PR run:

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub