This is needed because of following problem:
- :tests-mutes has `implementation` dependency on khttp library
- khttp has dependency on spek-junit-platform-engine library
- :tests-common had `testCompile` dependency on :tests-mutes which
added spek library as as a dependency to all modules which depend
on :tests-common, including :tests-common-new
Then, if project is configured with JPS then if user tries to run all
tests in directory in module which uses JUnit 5 (like :tests-common-new)
then spek library will be added to classpath and junit runner takes
some platform extension from it which causes NoSuchMethodException
because spek library was compiled against outdated JUnit 5 version
and current version doesn't have some API.
So splitting :tests-mutes for two parts fixes this issue, because common
part (:compiler:tests-mutes) no longer depends on khttp, so spek
library doesn't spreads to all modules
Bogdan Mukvich