Reproduction steps:
1. Create a new URP project
2. Open Render Pipeline Converter window (Window > Rendering > Render Pipeline Converter)
3. Enter Play mode 
4. Enable "Material reference Converter" or "Material Shader Converter"
5. Press "Initialize Converters"

Actual result: Progress window stuck
Expected result: Progress window finishes or cancels

Reproducible with: 6000.4.0a2, 6000.3.0.b4, 6000.2.6f2, 6000.1.17f1, 6000.0.58f2, 2023.3.0b10, 2022.3.62f1
Not reproducible with:  -

Note 1: It would probably be better just not allow user to initialize on play mode.

Note 2: The stuck is bit different depending on Unity versions:

- Stuck on creating search index and can not be cancelled, whole unity needs to be closed. [6000.2.6f2, 6000.1.17f1, 6000.0.58f2, 2023.3.0b10, 2022.3.62f1]

- Stuck can be closed when you {}exit the the play mode{}. [6000.4.0a2, 6000.3.0.b4]

Reproduced on: macOS Sequoia 15.7.1 (M1 Max)