Add kotlin-reflect to isolated KSP classpath

[monosoul]

KSP task loads kotlin-stdlib jar, which contains kotlin.jvm.internal.ClassReference. The classloader that loads this class is used as a parent classloader for actual processors. The processors might load kotlin-reflect library which contains kotlin.reflect.jvm.internal.KClassImpl (extends ClassReference). Since ClassReference is loaded in a different classloader, it can't be type cast to KClassImpl later on. That makes it impossible to use Kotlin reflection in KSP processors. Explicitly adding kotlin-reflect to the parent classloader fixes the issue.

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