Replace @Synchronized with ReentrantLock to avoid virtual thread pinning

[peacemaker123456]

I noticed that "synchronized" is being used in the form of the Kotlin annotation "@synchronized"
e.g. @synchronized internal fun trackFailure(call: RealCall, e: IOException?)

With virtual threads this leads to a problem called thread pinning. I suggest you replace it with something like ReentrantLock, like it was done here:

spring-projects/spring-framework@0b09f1e

[yschimke]

See #8371