Misaligned buttons in bevy_feathers showcase

[theotherphil]

In the top row of the showcase image on #19900, the right edge of the left button aligns with the row below, but the left edge of the right button does not.

[rparrett]

From discord:

Ah, I see. Yeah, I'm using flex_grow, and because the different buttons have different flex_basis (as determined by the text label) their eventual size comes out different.
DreamerTalin — 8:13 AM