Switch to Xcode 15 (with the iOS 16.4 Simulator for tests still) (#2113)

* Use Xcode 15 in GitHub actions.

Use iOS 16.4 simulators from Xcode 14 as iOS 17.0.1 simulators are **super** slow.

* Fix failing preview snapshots.

Snapshot fix.

* Improve setup

* Regenerate snapshots that had a conflict.

---------

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>

UnitTests/Sources/AudioPlayerStateTests.swift

@@ -21,6 +21,7 @@ import XCTest
 
 @MainActor
 class AudioPlayerStateTests: XCTestCase {
+    static let audioDuration = 10.0
     private var audioPlayerState: AudioPlayerState!
     private var audioPlayerMock: AudioPlayerMock!
     
@@ -48,8 +49,11 @@ class AudioPlayerStateTests: XCTestCase {
     override func setUp() async throws {
         audioPlayerActionsSubject = .init()
         audioPlayerSeekCallsSubject = .init()
-        audioPlayerState = AudioPlayerState(id: .timelineItemIdentifier(.random), duration: 10.0)
+        audioPlayerState = AudioPlayerState(id: .timelineItemIdentifier(.random), duration: Self.audioDuration)
         audioPlayerMock = buildAudioPlayerMock()
+        audioPlayerMock.seekToClosure = { [weak self] progress in
+            self?.audioPlayerMock.currentTime = Self.audioDuration * progress
+        }
     }
     
     func testAttach() async throws {