Remove old versionadded tags in the docs

docs/advanced_topics/customisation/rich_text_internals.rst

@@ -196,10 +196,6 @@ This method allows you to register a custom handler deriving from ``wagtail.core
         features.register_embed_type(MyCustomEmbedHandler)
 
 
-.. versionadded:: 2.5
-   In previous releases, ``register_link_type`` and ``register_embed_type`` accepted two arguments: the identifier for the link or embed type, and a function for performing the rewriting (equivalent to the ``expand_db_attributes`` method).
-
-
 Editor widgets
 --------------
 

docs/reference/contrib/modeladmin/create_edit_delete_views.rst

@@ -62,11 +62,10 @@ Or alternatively:
         ])
 
 
-.. versionadded:: 2.5
-   ``edit_handler`` and ``panels`` can alternatively be 
-   defined on a ``ModelAdmin`` definition. This feature is especially useful
-   for use cases where you have to work with models that are 
-   'out of reach' (due to being part of a third-party package, for example).
+``edit_handler`` and ``panels`` can alternatively be
+defined on a ``ModelAdmin`` definition. This feature is especially useful
+for use cases where you have to work with models that are
+'out of reach' (due to being part of a third-party package, for example).
 
 .. code-block:: python
 
@@ -204,7 +203,6 @@ on the Model itself is more complicated.
 -----------------------------------
 ``ModelAdmin.get_edit_handler()``
 -----------------------------------
-.. versionadded:: 2.5
 
 **Must return**: An instance of ``wagtail.admin.edit_handlers.ObjectList``