v3.42.0

• added: git machete status now annotates each branch checked out in a worktree with a [<worktree>] label (suggested by @mikechristiansenvae)
• fixed: git machete go, slide-out and {github,gitlab} checkout-{pr,mr}s now fail with an actionable error when the target branch is already checked out in another worktree, rather than the cryptic fatal: '<branch>' is already used by worktree at <path> from git checkout (reported by @lsierant)