Merge branch 'ds/branch-checked-out' into ds/rebase-update-ref

* ds/branch-checked-out:
  branch: drop unused worktrees variable
  fetch: stop passing around unused worktrees variable
  branch: fix branch_checked_out() leaks
  branch: use branch_checked_out() when deleting refs
  fetch: use new branch_checked_out() and add tests
  branch: check for bisects and rebases
  branch: add branch_checked_out() helper

diff --cc branch.c
Simple merge

diff --cc branch.h
Simple merge

diff --cc builtin/fetch.c
Simple merge