PHP8.1: Deprecated function: strrpos(): Passing null to parameter #1 ($haystack)

[laryn]

Deprecated function: strrpos(): Passing null to parameter #1 ($haystack) of type string is deprecated in metatag_favicons_get_mime_type() (line 95 of /app/modules/contrib/metatag/metatag_favicons/metatag_favicons.module).