Customizable Toolbar preset does not switch to the Unity Default Preset when Reverting All Saved Presets or deleting the active Preset

Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Click the Customizable Toolbar's burger button on the top right of the Editor
3. Click the "Presets > Save Preset"
4. Enter "asd" for the Preset Name property
5. Click the "Create" button
6. Repeat step 2
7. Click the "Presets > Revert All Saved Presets" or "Presets > Delete Preset > asd"
8. Repeat step 2
9. Observe the Presets dropdown

Actual results: The Unity Default preset is not selected

Expected results: The Unity Default preset is selected

Reproducible with versions: 6000.3.15f1, 6000.4.7f1, 6000.5.0b8, 6000.6.0a5

Can’t test with versions: 6000.0.75f1 (due to no Customizable Toolbar)

Tested on (OS): MacOS Silicon Tahoe 26.3