Deadlock on exiting Play Mode when a Shader is destroyed while async shader compilation has queued variant requests for a different shader with Graphics Jobs enabled

How to reproduce:
1. Open the attached Project
2. Run Tools -> Bug repro

Actual result: Editor deadlocks and is no longer responding, CPU usage drops to 0
Expected result: Process runs through 40 cycles and Editor can be used normally

Reproducible with: 6000.0.85f1, 6000.3.13f1, 6000.3.24f1,
Not reproducible with: 6000.3.12f1, 6000.6.2f1, 6000.7.0b2, 7000.0.0a1

Reproducible on: Windows 11
Not reproducible on: macOS 26.6.2 (M3 Pro)

Notes:

• Reporter noted "Requires Graphics Jobs enabled, Asynchronous Shader Compilation enabled, and Graphics API D3D12."
• Reporter noted the cause:

”If a shader is destroyed while asynchronous shader compilation still has pending work for a different shader, the Editor freezes permanently.

Exiting Play Mode triggers this reliably, because shaders created at runtime are destroyed as Play Mode ends, and that often happens while shader variants are still compiling in the background.”