Reproduction steps:
1. Open the attached project "ReproProj"
2. Open the “/Assets/Scenes/TestAwaitableAlloc.unity” Scene
3. Enter the Play Mode
4. Click the Button with the text "NextFrameAsync"
5. Click the Button with text “NextFrameAsyncCancellationToken“
6. Open Profiler window (Window > Analysis > Profiler)
7. In Profiler’s Hierarchy, go to “PlayerLoop > Update.ScriptRunDelayedDynamicFrameRate > CoroutinesDelayedCalls >Awaitable.OnUpdate() [Invoke] > GC.Alloc”
8. Observe the GC Alloc

Expected result: GC Alloc is 0 KB
Actual result: GC Alloc is 0.7 KB

Reproducible with: 6000.0.45f1, 6000.1.0b13, 6000.2.0a8
Could not test with: 2022.3.60f1 (Assets\Scenes\TestAwaitableAlloc.cs(29,15): error CS0246: The type or namespace name 'Awaitable' could not be found)

Reproducible on:
Play Mode
Windows Standalone Player

Testing environment: Windows 10 Enterprise 21H2
Not reproducible on: No other environment tested

Note:
- Discussions thread https://discussions.unity.com/t/does-awaitable-nextframeasync-cause-large-allocations-with-cancellationtoken/1620767