ICU-22545 Fix addLikelySubtags for pseudo Locales #1165

Job	Run time
clang-valgrind-test	16m 10s
clang-valgrind-intltest (utility)	9m 2s
clang-valgrind-intltest (normalize)	9m 14s
clang-valgrind-intltest (collator)	6m 13s
clang-valgrind-intltest (regex)	5m 26s
clang-valgrind-intltest (format)	23m 39s
clang-valgrind-intltest (translit)	6m 59s
clang-valgrind-intltest (rbbi)	8m 54s
clang-valgrind-intltest (rbnf)	7m 31s
clang-valgrind-intltest (rbnfrt)	7m 21s
clang-valgrind-intltest (icuserv)	6m 34s
clang-valgrind-intltest (idna)	6m 18s
clang-valgrind-intltest (convert)	8m 23s
clang-valgrind-intltest (rbnfp)	6m 4s
clang-valgrind-intltest (csdet)	7m 23s
clang-valgrind-intltest (spoof)	6m 6s
clang-valgrind-intltest (bidi)	8m 7s
	2h 29m 24s

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