localrepo: pass arbitrary kwargs from `repo.pull` to `exchange.pull`

We'll add bookmark-related arguments to `repo.pull` so we need to widen the
signature of `repo.pull`. We should probably kill `repo.pull` now that
`repo.push` is dead but this is outside the scope of this series.

mercurial/localrepo.py

@@ -1574,8 +1574,8 b' class localrepository(object):'
 
         return r
 
-    def pull(self, remote, heads=None, force=False):
-        return exchange.pull (self, remote, heads, force)
+    def pull(self, remote, heads=None, force=False, **kwargs):
+        return exchange.pull(self, remote, heads, force, **kwargs)
 
     def checkpush(self, pushop):
         """Extensions can override this function if additional checks have