CLDR-18392 Add warning about upcoming H24 deprecation (unicode-org#5080)

Co-authored-by: Fredrik <[email protected]>

Author: AEApple

docs/site/downloads/cldr-48.md

@@ -288,6 +288,7 @@ The following files are new in the release:
 
 ### V49 advance warnings
 The following changes are planned for CLDR 49. Please plan accordingly to avoid disruption.
+- [CLDR-18303][] H24 will be deprecated. If it is encountered, it will have H23 behavior. There is no known intentional usage of H24. If you have a current need for H24 instead of H23, please comment on [CLDR-18303][].
 - The default week numbering changes to ISO instead being based on the calendar week starting in CLDR 48 [CLDR-18275]. The calendar week will be more clearly targeted at matching usage in displayed month calendars.
 - The pre-Meiji Japanese eras will be removed: There was too much uncertainty in the exact values
 and feedback that the general practice for exact dates is to use Gregorian for pre-Meiji dates.
@@ -317,6 +318,7 @@ For web pages with different views of CLDR data, see [http://cldr.unicode.org/in
 [CLDR-14479]: https://unicode-org.atlassian.net/browse/CLDR-14479
 [CLDR-16004]: https://unicode-org.atlassian.net/browse/CLDR-16004
 [CLDR-16715]: https://unicode-org.atlassian.net/browse/CLDR-16715
+[CLDR-18303]: https://unicode-org.atlassian.net/browse/CLDR-18303
 [CLDR-18087]: https://unicode-org.atlassian.net/browse/CLDR-18087
 [CLDR-18113]: https://unicode-org.atlassian.net/browse/CLDR-18113
 [CLDR-18114]: https://unicode-org.atlassian.net/browse/CLDR-18114