Note that 3 tests are still muted, but for another reason: for FIR
versions of the tests, we need to compile the "pre-release library" with
the next language version which is 2.1. But since currently
LanguageVersion.LATEST_STABLE is 1.9, the compiler refuses to read
metadata of version 2.1, regardless of its own language version. Which
is correct, but it leads to irrelevant errors in the test output -- the
ones about the incompatible metadata version, NOT about the
prereleaseness.
These 3 tests can be unmuted once the default language version is
switched to 2.0.
#KT-60780 Fixed
Mikhail Glukhikh