ConditionLock deallocs its pthread_cond_t in more cases (#2901)

### Motivation:

Recently we changed the init and deinit behavior of `ConditionLock`, at
that time the `UnsafeMutablePointer` allocation of the held
`pthread_cond_t` was put behind a conditional compiler and runtime
check. The deallocation of the same object was also put behind a
conditional, however the conditions were mismatched leading to a leak on
some platforms. Notably this surfaced when `wait`ing on an event loop
future.

### Modifications:

`ConditionLock.deinit` now deallocs the held `pthread_cond_t` under the
same conditions in which it allocs it.

### Result:

Creating a `ConditionLock` no longer leaks memory.

Author: rnro

Sources/NIOConcurrencyHelpers/lock.swift

@@ -159,8 +159,6 @@ public final class ConditionLock<T: Equatable> {
         #elseif (compiler(<6.1) && !os(WASI)) || (compiler(>=6.1) && _runtime(_multithreaded))
         let err = pthread_cond_destroy(self.cond)
         precondition(err == 0, "\(#function) failed in pthread_cond with error \(err)")
-        #endif
-        #if compiler(>=6.1) && _runtime(_multithreaded)
         self.cond.deallocate()
         #endif
     }