[ci skip] Update EXTENSIONS and CODEOWNERS for ext/readline

I have read through the code base and done several patches, also I have
experience in working with this extension years ago.
Thus, I volunteer to receive a email in readline PRs and take the maintenance
work of this orphaned extension.

Author: LamentXU123

.github/CODEOWNERS

@@ -45,6 +45,7 @@
 /ext/pgsql @devnexen
 /ext/phar @LamentXU123
 /ext/random @TimWolla @zeriyoshi
+/ext/readline @LamentXU123
 /ext/reflection @DanielEScherzer
 /ext/session @Girgias @jorgsowa
 /ext/simplexml @devnexen

EXTENSIONS

@@ -420,8 +420,8 @@ STATUS:              Working
 SINCE:               8.2.0
 -------------------------------------------------------------------------------
 EXTENSION:           readline
-PRIMARY MAINTAINER:  Unknown
-MAINTENANCE:         Unknown
+PRIMARY MAINTAINER:  Weilin Du <weilindu@php.net> (2026 - 2026)
+MAINTENANCE:         Maintained
 STATUS:              Working
 -------------------------------------------------------------------------------
 EXTENSION:           reflection