How to reproduce:
1. Open the attached project's "case_1350635-Project.zip" Scene labeled "SampleScene"
2. Go to Preferences -> ProBuilder
3. Enable Experimental Features
4. Open the Boolean Tool (Tools -> ProBuilder -> Experimental -> Boolean (CSG) Tool)
5. In the opened window, select two 'Cube' GameObjects
6. Go through the 'Operations' and click 'Apply'

Expected result: Editor doesn't crash
Actual result: Editor crashes almost every time

Reproducible with: 5.0.3 (2020.3.15f1, 2021.1.16f1), 5.0.4 (2021.2.0b6, 2022.1.0a4)
Not reproducible with: 5.0.3 (2019.4.29f1) (Extensively tested with different shapes)

Note:
- Does not fail with simple shapes without editing their vertices