Fix T59381: UV editor - Pinned vertex missing update

Pinning doesn't really change the geometry, so we don't really have a
tag for this. Using '0' for now (same we use for Mark Seam).

I will check with Sergey Sharybin which flag to use instead.
We could use ID_RECALC_GEOMETRY to match the notifier, but even the
simpler ID_RECALC_SELECT would do it.

source/blender/editors/uvedit/uvedit_ops.c

@@ -3969,6 +3969,7 @@ static int uv_pin_exec(bContext *C, wmOperator *op)
 
 		if (changed) {
 			WM_event_add_notifier(C, NC_GEOM | ND_DATA, obedit->data);
+			DEG_id_tag_update(obedit->data, 0);
 		}
 	}
 	MEM_freeN(objects);