### Godot version

8449592d92eaeef990f5502b419d491ee3eeb7a6

### System information

Windows 11

### Issue description

Zooming in the script editor on an empty script freezes the entire editor for a few seconds, but if the file is large then it freezes for 4-5 seconds (which is unacceptable). Looks like a recent regression.

### Steps to reproduce

Just zoom in/out on the large script file.

### Minimal reproduction project

N/A
FontFallback *fd = font_owner.get_or_null(p_font_rid);
	ERR_FAIL_COND_V(!fd, String());
	MutexLock lock(fd->mutex);
	if (fd->cache.is_empty()) {
		ERR_FAIL_COND_V(!_ensure_cache_for_size(fd, fd->msdf ? Vector2i(fd->msdf_source_size, 0) : Vector2i(16, 0)), String());
	}
	FontForSizeFallback *at_size = fd->cache.begin()->value;
	String chars;
#ifdef MODULE_FREETYPE_ENABLED
	if (at_size && at_size->face) {
		FT_UInt gindex;
		FT_ULong charcode = FT_Get_First_Char(at_size->face, &gindex);
		while (gindex != 0) {
			if (charcode != 0) {
				chars = chars + String::chr(charcode);
			}
			charcode = FT_Get_Next_Char(at_size->face, charcode, &gindex);
		}
		return chars;
	}
#endif
	if (at_size) {
		const HashMap<int32_t, FontGlyph> &gl = at_size->glyph_map;
		for (const KeyValue<int32_t, FontGlyph> &E : gl) {
			chars = chars + String::chr(E.key);
		}
	}
	return chars;
}
void TextServerFallback::_font_render_range(const RID &p_font_rid, const Vector2i &p_size, int64_t p_start, int64_t p_end) {