feat(gradle): add support for java.toolchain.languageVersion detection in build.gradle(.kts) files

[Churro]

Changes

Support for Java toolchain definitions that are available since Gradle 6.7. During artifact updates of gradle lockfiles and gradle-wrapper, build.gradle and/or build.gradle.kts is checked for a pattern that is officially supported by gradle or by the Kotlin gradle plugin. If found, the declared Java major version is set as a constraint when running gradle.

Context

• Closes Support java.toolchain.languageVersion detection in build.gradle files #32023

Documentation (please check one with an [x])

• I have updated the documentation, or
• No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• Code inspection only, or
• Newly added/modified unit tests, or
• No unit tests but ran on a real repository, or
• Both unit tests + ran on a real repository

Test repo relying on Java 17 in build.gradle: https://github.com/renovate-demo/32023-toolchain