Refactor unsafe collections and benchmarks

Changed the `CollectionBenchmark` class to use unsafe code for improved memory operations and added benchmarks for stack-allocated arrays.
Changed the `ParallelNoiseBenchmark` class to remove the internal `NoiseJob` struct, promoting better organization.
Changed the `AllocationManager` class to remove the lock mechanism for thread safety and simplified the `Reset` method.
Changed the `Arena` and `DynamicArena` structs to include `Initialize` methods for better initialization control.
Changed the `UnsafeArray<T>`, `UnsafeHashSet<T>`, and `UnsafeList<T>` structs to improve element access and management.
Updated the `UnsafeCollectionExtensions` class to enhance usability with new methods for copying and converting collections.
Updated the `MemoryLeakException` class to provide more detailed stack trace information for better debugging.
Removed the usage of `UnsafeHashMap` in `Program.cs` and directly ran the `CollectionBenchmark`.
Added a new `NoiseJob` struct in `NoiseJob.cs` for generating gradient noise using `UnsafeArray<float>`.
Fixed minor typos and improved method signatures throughout the codebase for clarity.

Misaki.HighPerformance.Unsafe/Collections/UnsafeArray.cs

@@ -73,7 +73,7 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
     public readonly ref T this[int index]
     {
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        get => ref UnsafeUtilities.ReadArrayElementRef<T>(_buffer, index);
+        get => ref _buffer[index];
     }
 
     public readonly bool IsCreated
@@ -128,6 +128,7 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
         _allocator = Allocator.External;
     }
 
+    /// <inheritdoc/>
     public void Resize(int newSize)
     {
         if (newSize == _count)
@@ -139,20 +140,28 @@ public unsafe struct UnsafeArray<T> : IUnsafeCollection<T>
         _count = newSize;
     }
 
+    /// <inheritdoc/>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public readonly void Clear()
     {
         MemClear(_buffer, (nuint)(_count * sizeof(T)));
     }
 
+    /// <inheritdoc/>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public readonly void* GetUnsafePtr()
     {
         return _buffer;
     }
 
+    /// <inheritdoc/>
     public void Dispose()
     {
+        if (!IsCreated)
+        {
+            return;
+        }
+
         AllocationManager.Free(_buffer, _allocator);
 
         _buffer = null;