Fixes #21377 This marks all "defined" languages in the `.gitattributes` file so they are not removed if they are not of type `programming` or `markup`.  Co-authored-by: zeripath <art27@cantab.net> Co-authored-by: Lauris BH <lauris@nix.lv> Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>