Restore TocTree.get_toctree_ancestors()

Author: AA-Turner

CHANGES

@@ -21,6 +21,8 @@ Bugs fixed
   This will be removed in Sphinx 9.
 * Restored calls to ``Builder.add_{css,js}_file()``,
   which several extensions relied upon.
+* Restored the private API ``TocTree.get_toctree_ancestors()``,
+  which several extensions relied upon.
 
 Testing
 -------

sphinx/environment/adapters/toctree.py

@@ -508,6 +508,9 @@ def resolve(self, docname: str, builder: Builder, toctree: addnodes.toctree,
             includehidden=includehidden,
         )
 
+    def get_toctree_ancestors(self, docname: str) -> list[str]:
+        return [*_get_toctree_ancestors(self.env.toctree_includes, docname)]
+
     def get_toc_for(self, docname: str, builder: Builder) -> Node:
         return document_toc(self.env, docname, self.env.app.builder.tags)