NativeText.Substring(startIndex, allocator) allocates the substring with the source string's allocator when a different allocator is passed

How to reproduce:

1. Create and open a new Universal 3D project
2. Ensure that the “com.unity.collections” package is installed
3. In the Project window, create a new “Editor” folder
4. Import the attached “NativeTextSubstringAllocatorRepro” script into the created “Editor” folder and the attached “csc.rsp” file into the “Assets” folder (in the internal notes)
5. In the Menu bar, select “Tools” → “Bug Repros” → “NativeText Substring Allocator”
6. Observe the Console window

Actual result: The last log in the Console window is “rows=7 passed=4 flagged=3”
Expected result: The last log in the Console window is “rows=7 passed=7 flagged=0”

Reproducible with: 6000.0.0f1, 6000.7.0b6, 7000.0.0a10

Reproducible on: Windows 10 (by user), Windows 11
Not reproducible on: No other environments tested