templatekw: fix return type of {succsandmarkers} (BC)
A hybrid object represents a list/dict of values, but {succsandmarkers}
returns a list of template mappings.
This change means old-style list templates (e.g. "start_succsandmarkers")
are no longer supported, but that should be okay since {succsandmarkers}
is still experimental and relatively new.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}