Reproduction steps:
1. Open the attached project “leak.zip“
2. Open a second Game view window (Right click on Game view tab > Add tab > Game)
3. Undock the new Game view window from the Editor
4. Set the Display to “Display 2” in the second Game view Window and snap the window to any side (Windows button + right arrow)
5. Open "Assets/Scenes/SampleScene.unity" scene
6. Enter the Play Mode
7. Unfocus the Editor
8. Observe memory usage
9. If memory usage didn't change unsnap the second Game view

Expected result: Memory usage is the same
Actual result: Memory leaks

Reproducible with: 2023.1.0b1, 2023.1.0b19, 2023.2.0a16
Couldn't test with: 2021.3.26f1, 2022.3.0f1, 2023.1.0a26 - (step 4 cannot be done)

Reproducible on: Windows 10

Notes:
Allocated memory goes back down to normal after focusing the editor again
Snapping Game view might not be necessary, but seems to be more consistent that way
GPU usage seems to go up a lot from undocking the second Game view