Revert "Fix #122808: Use Default Font when Vfont Missing"

This reverts commit 26ea1f42c3.

In line with [0] which prevents default characters from being used when
a font is selected, don't return characters from the default font when
the font cannot be loaded.

This should be addressed using place holder characters instead.

[0]: 6fa5295c1d

source/blender/blenkernel/intern/vfontdata_freetype.cc

@@ -103,10 +103,7 @@ VChar *BKE_vfontdata_char_from_freetypefont(VFont *vfont, ulong character)
   }
 
   if (font_id == -1) {
-    /* This could happen for a saved file with an unpacked local font that was
-     * later removed. Load the default UI font so we can still show _something_. */
-    font_id = BLF_load_mem(
-        vfont->data->name, static_cast<const uchar *>(builtin_font_data), builtin_font_size);
+    return nullptr;
   }
 
   VChar *che = (VChar *)MEM_callocN(sizeof(VChar), "objfnt_char");