No x-axis margin for discard and new pull request buttons causes overflow

[noahbclarkson]

Description

Discard and new pull request buttons in dialog touch or extend past the right-hand side of the dialog incorrectly.

Steps to Reproduce

1. Open rgitui
2. Click Discard x on unstaged file or Create PR button

Expected Behavior

Correct UI

Actual Behavior

Incorrect padding/margin between button and right-hand side of the dialog.

Environment

Windows

Version

0.1.6

Additional Context

No response