Revert "Make Atomic.deinit @_transparent"

This reverts commit dd037f8.

@_transparent on deinit was diagnosed as an error in older compilers

Making Atomic.deinit @_transparent will break compiling newer sdk with older compilers

Fixes rdar://139194948

Author: meg-gupta

stdlib/public/Synchronization/Atomics/Atomic.swift

@@ -42,10 +42,11 @@ public struct Atomic<Value: AtomicRepresentable>: ~Copyable {
     _address.initialize(to: Value.encodeAtomicRepresentation(initialValue))
   }
 
+  // Deinit's can't be marked @_transparent. Do these things need all of these
+  // attributes..?
   @available(SwiftStdlib 6.0, *)
   @_alwaysEmitIntoClient
   @inlinable
-  @_transparent
   deinit {
     let oldValue = Value.decodeAtomicRepresentation(_address.pointee)
     _ = consume oldValue