When a file is deleted pages using that file should be added to [[Category:Pages with broken file links]].
It looks like this is not done automatically when a file is deleted. You have to wait for some other action
to trigger category updates for those pages (I think page edit, template edit, wikidata item edit, and maybe
other actions). This can take a long time, more than at least a month in some cases.

I think file deletion should cause category update on all pages using the file, the same as template edit
does to all pages using a template. Category updates after template edits usually happens very soon after
the edit and rarely takes more than a day.

Example:
[[Commons:File:Election posters European Parliament election in Copenhagen Denmark 2009.jpg]] was deleted
on December 3 2020. [[sv:Europaparlamentsvalet i Danmark 2009]] used this file and was added to
[[sv:Kategori:Sidor med trasiga fillänkar]] on timestamp 2021-01-17T08:44:55Z, one and a half month later.
Probably because of an edit to [[sv:Template:Navbox]] on January 16.