mpv: Use Iosevka as OSD font

This still had an impure dependency on a proprietary font.

users/simon/modules/mpv/default.nix

@@ -69,7 +69,7 @@ in
 
     config = {
       # Main application font
-      osd-font = "DINW07-Medium"; # not included in repository (unfree)
+      osd-font = "Iosevka Nerd Font";
 
       # Subtitles (adapted from https://github.com/LightArrowsEXE/dotfiles/blob/75973b6c8493368bbdee6e8e632964045fcf22ec/mpv/.config/mpv/mpv.conf#L76)
       sub-bold = true;
@@ -252,8 +252,8 @@ in
   '';
 
   xdg.configFile."mpv/script-opts/stats.conf".text = ''
-    font=DINW07-Regular
-    font_mono=DINW07-Regular
+    font=${config.programs.mpv.config.osd-font}
+    font_mono=${config.programs.mpv.config.osd-font}
     font_size=10
     redraw_delay=0.25
   '';