removed type annotation to fix pipeline

fgs/datatypes.py

@@ -546,7 +546,7 @@ class Link:
             return self.url
     urlwithanchor = property(get_urlwithanchor, None, None)
 
-    def get_rel(self) -> str|None:
+    def get_rel(self):
         """
         Get the relation in the context of the rel html attribute for this link
         or None if no relation is known.