Use JaCoCo 0.8.5 by default

[Godin]

Context

This JaCoCo release provides new features which are of particular interest for

• early adopters of Java 14
• for developers who use Kotlin compiler

And it contains general bug fixes, full changelog - http://www.jacoco.org/jacoco/trunk/doc/changes.html

Contributor Checklist

• Review Contribution Guidelines
• Make sure that all commits are signed off to indicate that you agree to the terms of Developer Certificate of Origin.
• Check "Allow edit from maintainers" option in pull request so that additional changes can be pushed by Gradle team
• Provide integration tests (under <subproject>/src/integTest) to verify changes from a user perspective
• Provide unit tests (under <subproject>/src/test) to verify logic
• Update User Guide, DSL Reference, and Javadoc for public-facing changes
• Ensure that tests pass locally: ./gradlew <changed-subproject>:check

Gradle Core Team Checklist

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation
• Recognize contributor in release notes

[big-guy]

I cherry-picked this to release so it'll be in 6.0.

[Godin]

@big-guy thank you! 👍 ❤️