CLDR-18108 Remove und entry

`und` -> `Latn` makes sense in many context, but `Zyyy` (Undetermined) may make sense as well. To avoid unanticipated side-effects, let's remove this row and only add it in if we need it.

Author: conradarcturus

tools/cldr-code/src/main/resources/org/unicode/cldr/util/data/language_script.tsv

@@ -883,7 +883,6 @@ uga	Ugaritic	primary	Ugar	Ugaritic
 uk	Ukrainian	primary	Cyrl	Cyrillic
 uli	Ulithian	primary	Latn	Latin
 umb	Umbundu	primary	Latn	Latin
-und	Unknown	primary	Latn	Latin
 unr	Mundari	primary	Beng	Bangla
 unr	Mundari	primary	Deva	Devanagari
 unx	Munda	primary	Beng	Bangla