[6.2] Fixes a few issues with `swift package {migrate, add-setting}` commands#8812

xedin merged 5 commits intoswiftlang:release/6.2swiftlang/swift-package-manager:release/6.2from

xedin:migration-fixes-6.2xedin/swift-package-manager:migration-fixes-6.2Copy head branch name to clipboard