RNA: expose the language enum to Python scripts

As far as I know it wasn't possible for scripts to access language
ID's and their names using documented API's.

Ref !147769

source/blender/makesrna/intern/rna_userdef.cc

@@ -5340,6 +5340,8 @@ static void rna_def_userdef_view(BlenderRNA *brna)
   /* Language. */
 
   prop = RNA_def_property(srna, "language", PROP_ENUM, PROP_NONE);
+  /* Set this flag so scripts can access language information at run-time via `enum_items`. */
+  RNA_def_property_flag(prop, PROP_ENUM_NO_CONTEXT);
   RNA_def_property_enum_items(prop, rna_enum_language_default_items);
 #  ifdef WITH_INTERNATIONAL
   RNA_def_property_enum_funcs(prop, nullptr, nullptr, "rna_lang_enum_properties_itemf");