UI Toolkit's Buttons don't fully expand when placed inside ToggleButtonGroup

Reproduction steps:
1. Open the attached “Tanks_Complete.zip” project
2. Open the “MainDemo” Scene
3. Select the “PlayManager” GameObject in the Hierarchy
4. Unravel the “Full Inspector” property in the Inspector’s “Play Manager (Script)” Component
5. Observe the buttons inside the “Game State” property

Expected Result: The “Game State” enum’s property drawer results in buttons that expand to the full width on the right of the label
Actual Result: The “Game State” enum's property drawer results in narrow buttons

Reproducible with: 2023.2.9f1, 2023.3.0b6
Couldn’t test with: 2021.3.34f1, 2022.3.19f1 (Unfixable compiler errors associated with UI Toolkit)

Reproducible on: Windows 11
Not reproducible on: no other environment tested

Note:

• Looking at the buttons' styles, their width is fixed to 12.25%