Cleanup: update workarounds for updated dependencies and Kotlin versions

[murfel]

Search for words like workaround, fix, fixed, etc. in the codebase and update the corresponding API usage.

#4557 (comment)

Example:

Since KT-62423 is fixed

https://github.com/Kotlin/kotlinx.coroutines/blob/master/kotlinx-coroutines-test/common/src/TestBuilders.kt#L608

https://github.com/Kotlin/kotlinx.coroutines/blob/master/kotlinx-coroutines-core/common/src/internal/LocalAtomics.common.kt#L9

[murfel]

From @fzhinkin

You can remove AtomicBoolean and replace it with kotlin.concurrent.atomics.AtomicBoolean
You can remove LocalAtomicInt and replace it with kotlin.concurrent.atomics.AtomicInt
The second option is a bit more difficult because it will contain a namespace with AFU. A possible solution is to make the internal typealias LocalAtomicInt = kotlin.concurrent.atomics.AtomicInt

[murfel]

Also search for YouTrack ticket references KT-\d\d\d\d\d