legacy: fix debugrecordpruneparents to call obsstore.create() with keywords It appears the API was changed twice in Mercurial at - 570f87422f54 "obsstore: add an explicit `date` argument to obsstore.create" - adb3798dce49 "obsstore: add a `parents` argument to obsstore.create" and metadata would be changed to a list of (key, value) pairs. Convert it back to a dict as expected by create().

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