cleanup: remove check only needed for hg versions before 4.4 ui.edit() has had the "action" argument since 6e6452bc441d (editor: use an unambiguous path suffix for editor files, 2017-08-30), which was first released in hg version 4.4. Since we support only versions higher than 4.5, we can drop this check.

test-drop.t
test-inhibit.t
test-simple4server.t
tests/test-simple4server-bundle2.t