Merge branch 'ps/setup-drop-global-state'

The refactoring of 'setup.c' has been continued to drop remaining global state (`git_work_tree_cfg`, `is_bare_repository_cfg`), updating `is_bare_repository()` to no longer implicitly rely on `the_repository`. * ps/setup-drop-global-state: treewide: drop USE_THE_REPOSITORY_VARIABLE environment: stop using `the_repository` in `is_bare_repository()` environment: split up concerns of `is_bare_repository_cfg` builtin/init: stop modifying `is_bare_repository_cfg` setup: remove global `git_work_tree_cfg` variable builtin/init: simplify logic to configure worktree builtin/init: stop modifying global `git_work_tree_cfg` variable