com.unity.collections 2.1.1 Package Notes

`IJobParallelBatch` provides `.Schedule`, `.ScheduleByRef`, `.ScheduleParallel`, `.ScheduleParallelByRef`, `.Run` and .`RunByRef` forms. `.ScheduleParallel` is equivalent to calling `.ScheduleBatch`.
Added `Trim`, `TrimStart`, `TrimEnd`, `ToLowerAscii`, `ToUpperAscii` methods to strings.
`NativeQueue.ReadOnly`.
`UnsafeParallelHashMap.ReadOnly`.
UnsafeQueue container type
`Unsafe/NativeParallelMultiHashMap.ReadOnly` view into container.
`UnsafeList.ReadOnly` enumerator.

Added additional `UNITY_DOTS_DEBUG` checks to collection types to help with standalone player debugging (since `ENABLE_UNITY_COLLECTION_CHECKS` safety checks are unavailable in standalone player builds)
Updated Burst version to 1.8.4
Reduced the amount of memory allocated by allocating based on the maximum number of worker threads the running platform requires rather than defaulting to using a theoretical upper-bound of 128 worker threads.

Calling `Dispose` on uninitialized container will not throw.
Properly tracks allocations made from the collections package such that when `Unity.Collections.NativeLeakDetectionMode` is `NativeLeakDetectionMode.Enabled` or `NativeLeakDetectionMode.EnabledWithStackTrace`, native memory leaks will be reported upon domain reload.
UnsafeParallelHashSet.ReadOnly was not usable in jobs due to extraneous [NativeContainer] attribute
NativeRingQueue.Dispose(JobHandle) allowed scheduling as a race condition
Dispose(JobHandle) for many native containers adhere to proper safety system expectations
Lowered benchmark memory usage in non-desktop player builds to avoid out-of-memory failures
Fixed container types could provide unaligned access to `T` elements which could violate platform alignment requirements resulting in native exceptions / crashes in player builds. All fixed types like `FixedList` now provide 8 byte alignment for the `FixedList` type itself, whereas the elements `T` remain naturally aligned in the contiguous storage buffer inside `FixedList`

com.unity.collections 2.1.1