Input doesnt ignore capitalization of file extension for bulk selection

[MisterSirCode]

By default, running heif-convert *.heic doesnt seem to select files like .HEIC, which are what apple tends to name files by default, or what many file trasnfer programs seem to rename them to for whatever reason.

Im writing a simple script to make this convenient for my folks who are using the tool in a little shortcut, and I want it to be able to accept any capitalization of heic.

Can this possibly be added, or an option to ignore capitalization of input files?