doc: fix broken AHAFS link in fs doc

The content we're linking to for AHAFS was published in 2011 but has now
been archived. This updates the link to the archived version (as the
current version results in a "Yikes!" page with an HTTP 400 response
code).

Unfortunately, the archived version does say "This content is no
longer being updated or maintained. The content is provided “as is.”
Given the rapid evolution of technology, some content, steps, or
illustrations may have changed." So we'll want to update at some point I
imagine. But for the moment, archived content with a notice like that is
better than a broken link.

PR-URL: #38534
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Ash Cripps <acripps@redhat.com>
Reviewed-By: Beth Griggs <bgriggs@redhat.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: Trott

doc/api/fs.md

@@ -6629,7 +6629,7 @@ the file contents.
 [Readable Stream]: stream.md#stream_class_stream_readable
 [Writable Stream]: stream.md#stream_class_stream_writable
 [caveats]: #fs_caveats
-[`AHAFS`]: https://www.ibm.com/developerworks/aix/library/au-aix_event_infrastructure/
+[`AHAFS`]: https://developer.ibm.com/articles/au-aix_event_infrastructure/
 [`Buffer.byteLength`]: buffer.md#buffer_static_method_buffer_bytelength_string_encoding
 [`FSEvents`]: https://developer.apple.com/documentation/coreservices/file_system_events
 [`Number.MAX_SAFE_INTEGER`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER