fix(codeberg): fix merged button text

[scarcekoi]

🗒 Checklist 🗒

• I have read and followed Catppuccin's userstyle contributing guidelines.

• I used AI (or AI-assistance) for this change.

🔧 What does this fix? 🔧

Closes: #2224

This fixes the merged buttons.

Before	After

🔍 Reproduction Steps 🔍

1. Go to a merged PR (e.g.: https://codeberg.org/Codeberg-Infrastructure/forgejo/pulls/132).
2. Look at the merged button which is below the header.

[uncenter]

This might be better fixed upstream with patching --color-white to be base instead of text.