Shader's _CameraDepthTexture is not read when the Camera is rendering to a RenderTexture and has a reduced viewport

Reproduction steps:
1. Open the attached “Repro“ project
2. Open the “Assets/Scenes/SampleScene.unity“ Scene
3. Open the Frame Debugger (Window > Analysis > Frame Debugger)
4. Enable it by pressing the “Enable“ button in the upper-left corner
5. Select Event #13 “Draw Mesh Depth Quad“ and observe the Game View
6. Select Event #6 “Draw Mesh Depth Quad“ and observe the Game View

Expected result: A black circle and a white background is seen like in Event #13
Actual result: Only the white background is seen

Reproducible with: 2021.3.36f1, 2022.3.20f1, 2023.2.10f1, 2023.3.0b7

Reproducible on: Windows 10 (22H2)
Not reproducible on: M1 MacOS 14.3.1

Note: This issue is only reproducible with DX11 or DX12 Graphics APIs. No reproduction on Metal and Vulkan.