ICU-22533 Don't mention 'Release Candidate' in javadoc #1191

Job	Run time
clang-valgrind-test	10m 7s
clang-valgrind-intltest (utility)	6m 41s
clang-valgrind-intltest (normalize)	7m 29s
clang-valgrind-intltest (collator)	6m 2s
clang-valgrind-intltest (regex)	5m 21s
clang-valgrind-intltest (format)	16m 11s
clang-valgrind-intltest (translit)	5m 54s
clang-valgrind-intltest (rbbi)	7m 8s
clang-valgrind-intltest (rbnf)	7m 58s
clang-valgrind-intltest (rbnfrt)	8m 39s
clang-valgrind-intltest (icuserv)	5m 55s
clang-valgrind-intltest (idna)	5m 21s
clang-valgrind-intltest (convert)	6m 37s
clang-valgrind-intltest (rbnfp)	5m 3s
clang-valgrind-intltest (csdet)	5m 6s
clang-valgrind-intltest (spoof)	5m 5s
clang-valgrind-intltest (bidi)	5m 8s
	1h 59m 45s

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