Revert "Add bitcoin to native sponsorship button in github"
Revert "Add bitcoin to native sponsorship button in github"

This reverts commit 07584c14ad9024de8c0d88ea30fbce780c46e7b9. Apparently
GitHub sponsors doesn't support bitcoin links, so that sucks.

DeathCradle/Open-Terraria-API,DeathCradle/Open-Terraria-API