Fix wrong link in the documentation of TopologicalSubmanifold.open_subset (Trac #34565)

Author: egourgoulhon

src/sage/manifolds/topological_submanifold.py

@@ -294,8 +294,7 @@ def open_subset(self, name, latex_name=None, coord_def={}, supersets=None):
 
         OUTPUT:
 
-        - the open subset, as an instance of
-          :class:`~sage.manifolds.manifold.topological_submanifold.TopologicalSubmanifold`
+        - the open subset, as an instance of :class:`TopologicalSubmanifold`
 
         EXAMPLES::