Merge branch 'hv/receive-denycurrent-everywhere'

Merge branch 'hv/receive-denycurrent-everywhere'

"git push" should stop from updating a branch that is checked out
when receive.denyCurrentBranch configuration is set, but it failed
to pay attention to checkouts in secondary worktrees.  This has
been corrected.

* hv/receive-denycurrent-everywhere:
  t2402: test worktree path when called in .git directory
  receive.denyCurrentBranch: respect all worktrees
  t5509: use a bare repository for test push target
  get_main_worktree(): allow it to be called in the Git directory