Resolve UnmanagedArray<T> obsolescence warnings

While generating documentation using docfx, I encountered 14 warnings related to the use of UnmanagedArray<T>, which has been marked as obsolete. The recommended approach is to obtain Memory<T> using GC.Allocate*Array or through a Stride-specific allocator mechanism. Addressing these warnings will enhance our codebase's cleanliness and maintainability. Below are examples of the warnings:

1. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Audio\CompressedSoundSource.cs(20,24): warning CS0618: 'UnmanagedArray<short>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
2. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\IHeightStickArraySource.cs(26,24): warning CS0618: 'UnmanagedArray<T>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
3. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\HeightStickArraySourceFromHeightmap.cs(34,31): warning CS0618: 'UnmanagedArray<T>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
4. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\ByteHeightStickArraySource.cs(45,31): warning CS0618: 'UnmanagedArray<T>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
5. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\Shapes\HeightfieldColliderShape.cs(129,16): warning CS0618: 'UnmanagedArray<short>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
6. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\Shapes\HeightfieldColliderShape.cs(131,16): warning CS0618: 'UnmanagedArray<byte>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
7. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\Shapes\HeightfieldColliderShape.cs(133,16): warning CS0618: 'UnmanagedArray<float>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
8. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\ShortHeightStickArraySource.cs(45,31): warning CS0618: 'UnmanagedArray<T>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
9. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\Shapes\HeightfieldColliderShape.cs(42,86): warning CS0618: 'UnmanagedArray<short>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
10. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\Shapes\HeightfieldColliderShape.cs(47,86): warning CS0618: 'UnmanagedArray<byte>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
11. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\Shapes\HeightfieldColliderShape.cs(52,86): warning CS0618: 'UnmanagedArray<float>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
12. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\FloatHeightStickArraySource.cs(35,31): warning CS0618: 'UnmanagedArray<T>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
13. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\Data\HeightfieldColliderShapeDesc.cs(81,24): warning CS0618: 'UnmanagedArray<T>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'
14. warning: D:\Projects\GitHub\stride\sources\engine\Stride.Physics\UnmanagedArrayExtensions.cs(18,41): warning CS0618: 'UnmanagedArray<T>' is obsolete: 'Obtain Memory<T> using GC.Allocate*Array or a Stride-specific allocator mechanism.'

Start by running the documentation generation with docfx and reviewing UnmanagedArrayExtensions.cs alongside the listed audio and physics call sites. Trace how each UnmanagedArray is allocated and apply the recommended Memory or Stride-specific allocator approach consistently; done means the 14 CS0618 warnings no longer appear.