Ensure TTF system is torn down in correct order (#21707)

`TTFDispose` uses `gCurrentTTFFontSet` to deallocate internal resources.
Having the function called after global variable got changed meant it
tried to deallocate incorrect font and would subsequently call
`FT_Done_Face` on a struct having internal data set to nullptr.

Reproduction is fairly easy:
1. launch the game in Korean (I made sure to have all the indexes primed
   for this language beforehand - i.e. launch it twice),
2. switch to Japanese,
3. switch back to Korean

Fixes #21664

src/openrct2/interface/Fonts.cpp

@@ -117,10 +117,11 @@ static void LoadSpriteFont(LocalisationService& localisationService)
 #ifndef NO_TTF
 static bool LoadFont(LocalisationService& localisationService, TTFFontSetDescriptor* font)
 {
+    TTFDispose();
     localisationService.UseTrueTypeFont(true);
+
     gCurrentTTFFontSet = font;
 
-    TTFDispose();
     bool fontInitialised = TTFInitialise();
     return fontInitialised;
 }