Increased Memory usage when Update Mode 'On Demand' Realtime lights are used and DX12 API is selected

Reproduction steps:
1. Open the attached “lights-memory-tests.zip” project
2. Open the “OutdoorsScene”
3. Build and Run the Project
4. After the Player is built, open Task Manager
5. Observe the Memory usage of the Player (lightsmemory.exe)

Expected result: The Player uses around 600 MB of memory
Actual result: The Player uses around 1.3 GB of memory

Reproducible with: 2021.3.46f1, 2022.3.52f1, 6000.0.30f1, 6000.1.0a7

Reproducible on: Windows 11
Not reproducible on: no other environment tested

Reproduces on both DX12 and Vulkan.

Notes:

• Pressing ‘Space’ on the keyboard calls “RequestShadowMapRendering()” on every light and pressing it a few times can increase the memory to up to 2 GB
• Does not seem to affect DX11 builds as the memory there stays under 600-700 MB
• In 2021.3 the memory usage was ~1.5 GB, 2022.3 ~1.4 GB, 6000.0 ~ 1.7 GB and 6000.1 ~1.7 GB
• The more Cube GameObjects there are in the Scene, the higher the memory usage is