bugfix-2.1.x
🔨 Drop obsolete env STM32F103CB_malyan_maple
🔨 Rename "BTT" things, MCU-based SKR 2 (#27319)
🎨 Some chmod ug-x
🐛 Fix macOS simulator build on Homebrew + Xcode CLT (#28491)
🎨 Misc patches from ProUI