Catch ValueError in clean_fandom_page when looking for subheadings.

exts/fandom_wiki.py

@@ -104,14 +104,24 @@ def clean_fandom_page(element: etree._Element) -> etree._Element: # type: ignor
 
  toc = element.find(".//div[@id='toc']")
  if toc is not None:
- if element.index(toc) > summary_end_index:
- summary_end_index = element.index(toc)
+ try:
+ index = element.index(toc)
+ except ValueError:
+ pass
+ else:
+ if index > summary_end_index:
+ summary_end_index = index
  toc.getparent().remove(toc) # type: ignore [reportOptionalMemberAccess]
 
  subheading = element.find(".//h2")
  if subheading is not None:
- if element.index(subheading) > summary_end_index:
- summary_end_index = element.index(subheading)
+ try:
+ index = element.index(subheading)
+ except ValueError:
+ pass
+ else:
+ if index > summary_end_index:
+ summary_end_index = index
  subheading.getparent().remove(subheading) # type: ignore [reportOptionalMemberAccess]
 
  if summary_end_index != 0: