RFR: 8366105: Update link to the external RuleBasedBreakIterator documentation

[Naoto Sato]

On Mon, 25 Aug 2025 15:18:51 GMT, Volker Simonis <simonis at openjdk.org> wrote:

> The JavaDoc of `sun.text.RuleBasedBreakIterator` contains the following link to "Text Boundary Analysis in Java" by Richard Gillam which describes its implementation details:
> 
> http://www.ibm.com/java/education/boundaries/boundaries.html
> 
> This link isn't online anymore since at least 2001, but fortunately its original content can still be found trough archive.org at https://web.archive.org/web/20001117163900/http://www.ibm.com/java/education/boundaries/boundaries.html
> 
> Replace the naked link text with the title and author of the publication and the link target with a new link to the ICU project which is still available: https://icu-project.org/docs/papers/text_boundary_analysis_in_java/

LGTM. Please update the copyright year

-------------

PR Review: https://git.openjdk.org/jdk/pull/26930#pullrequestreview-3152459657