STAT_StaticMeshTotalMemory increases after repeated loading and unloading of a level containing Nanite static meshes

The issue appears to be caused by a mismatch in the value returned by GetResourceSizeBytes(EResourceSizeMode::Exclusive) between InitResources() and ReleaseResources().

At InitResources(), the reported size includes Nanite-related data. However, by the time ReleaseResources() is called, the Nanite data is already reduced or no longer present. As a result, the value subtracted during release is smaller than the value added during initialization.

1. Duplicate the following Static Mesh into the project directory:
   /Engine/EditorMeshes/Cascade/BackgroundCube
2. Enable Nanite on the duplicated mesh.
3. Create a new Empty Level and place the Nanite-enabled mesh in the level.
4. Create a new Basic Level, and add the previous level as a SubLevel.
5. Implement a mechanism to repeatedly load and unload the SubLevel.
   Example: In the Level Blueprint, bind a key input event.
   Use Load Stream Level and Unload Stream Level nodes to toggle the SubLevel.
6. Package and run the project.
7. Execute console command: stat memory
8. Repeatedly load and unload the SubLevel.

Results:
STAT_StaticMeshTotalMemory increases after each load/unload cycle.

Expected Results:
Repeated load/unload cycles should not cause cumulative increases in this stat.