Steps to reproduce:
1. Open attached EditorWindowTests.zip project (make sure Library folder is deleted before opening)
2. Open toolbar item Tests -> Test Runner (Generate References)
3. Press "Run All"
4. Observe console window

Expected result: All assets import without issues
Actual result: Warnings/errors thrown
Calling Deallocate on pointer, that can not be deallocated by allocator ALLOC_TEMP_PreviewLoader
Calling Deallocate on pointer, that can not be deallocated by allocator ALLOC_TEMP_MAI
Allocation of 4608 bytes at 00000262407A27D0
Assertion failed: TLS Allocator ALLOC_TEMP_TLS, underlying allocator ALLOC_TEMP_MAIN has unfreed allocations, size 4608
Internal: Stack allocator ALLOC_TEMP_MAIN has unfreed allocations, size 4608
To Debug, run app with -diag-temp-memory-leak-validation cmd line argument. This will output the callstacks of the leaked allocations.

Reproduced with: 2022.1.0b9, 2022.1.0b8
Didn't reproduce with: 2022.2.0a5, 2022.1.0b7, 2021.2.12f1, 2020.3.29f1, 2019.4.36f1

Note: Only seems to reproduce the first time the project is imported, restarting the editor fixes the issue and subsequent imports do not throw any alloc errors