Merge branch 'jk/alias-in-bare' into maint

An aliased command spawned from a bare repository that does not say it is bare with "core.bare = yes" is treated as non-bare by mistake. * jk/alias-in-bare: setup: suppress implicit "." work-tree for bare repos environment: add GIT_PREFIX to local_repo_env cache.h: drop LOCAL_REPO_ENV_SIZE