Fix deprecated destinationDir property

[helfper]

This PR fixes this warning:

The AbstractCompile.destinationDir property has been deprecated. This is scheduled to be removed in Gradle 8.0. Please use the destinationDirectory property instead. Consult the upgrading guide for further information: https://docs.gradle.org/7.1/userguide/upgrading_version_7.html#compile_task_wiring

As well as, some other deprecations and minor clean-ups.

[maiflai]

thanks - dare i ask if you've tried upgrading this to gradle 8?

[helfper]

I don't think there's Gradle 8 yet -- the nightly build is still on 7.3. I was just trying to get rid of the warnings as I always run my builds with --warning-mode=all. AbstractCompile.destinationDirectory exists since Gradle 6.1, so this change should still be compatible with that version (not sure what's the minimum required Gradle version by gradle-scoverage at the moment).

Before being able to run this plugin in Gradle 8, there are still more deprecations that need to be solved though, which can now be seen in the GitHub Actions logs, like this one:

Gradle detected a problem with the following location: '/home/runner/work/gradle-scoverage/gradle-scoverage/build/resources/functionalTest/projects/scala-single-module-multiple-test-tasks'. Reason: Task ':reportTestScoverage' uses this output of task ':compileIntTestJava' without declaring an explicit or implicit dependency. This can lead to incorrect results being produced, depending on what order the tasks are executed. Please refer to https://docs.gradle.org/7.1/userguide/validation_problems.html#implicit_dependency for more details about this problem. This behaviour has been deprecated and is scheduled to be removed in Gradle 8.0. Execution optimizations are disabled to ensure correctness. See https://docs.gradle.org/7.1/userguide/more_about_tasks.html#sec:up_to_date_checks for more details.

[maiflai]

Yes - I've been trying to solve those as part of the --parallel fix, but it's not very straightforward as far as I can see.

Thanks for the tidy up :-)