ByteBuffer: one fewer allocs to go to Data (#1839)

Motivation:

When getting a `Data` from a `ByteBuffer` we currently allocate twice
(`__DataStorage`) and the closure for `Data.Deallocator`.

Modifications:

We can optimise that by making the closure capture exactly one
`AnyObject` which is already a reference counted object. The compiler
realises that (on Linux) and saves us an alloc.

Thanks @Lukasa for the suggestion here:
#1836 (comment)

Result:

Fewer allocs.

Sources/NIOFoundationCompat/ByteBuffer-foundation.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the SwiftNIO open source project
 //
-// Copyright (c) 2017-2021 Apple Inc. and the SwiftNIO project authors
+// Copyright (c) 2017-2024 Apple Inc. and the SwiftNIO project authors
 // Licensed under Apache License v2.0
 //
 // See LICENSE.txt for license information
@@ -126,11 +126,11 @@ extension ByteBuffer {
                     count: Int(length)
                 )
             } else {
-                _ = storageRef.retain()
+                let storage = storageRef.takeUnretainedValue()
                 return Data(
                     bytesNoCopy: UnsafeMutableRawPointer(mutating: ptr.baseAddress!.advanced(by: index)),
                     count: Int(length),
-                    deallocator: .custom { _, _ in storageRef.release() }
+                    deallocator: .custom { _, _ in withExtendedLifetime(storage) {} }
                 )
             }
         }