[ci skip] Add myself to tidy extension maintainers

I've been looking after this de-facto, and can review PRs.
This doesn't add much extra workload anyway.

Author: ndossche

.github/CODEOWNERS

@@ -52,6 +52,7 @@
 /ext/sockets @devnexen
 /ext/spl @Girgias
 /ext/standard @bukka
+/ext/tidy @nielsdos
 /ext/xml @nielsdos
 /ext/xmlreader @nielsdos
 /ext/xmlwriter @nielsdos

EXTENSIONS

@@ -510,6 +510,7 @@ EXTENSION:           tidy
 PRIMARY MAINTAINER:  John Coggeshall <john@php.net> (2003 - 2006)
                      Ilia Alshanetsky <iliaa@php.net> (2003 - 2009)
                      Nuno Lopes <nlopess@php.net> (2006 - 2012)
+                     Niels Dossche <nielsdos@php.net> (2025 - 2025)
 MAINTENANCE:         Maintained
 STATUS:              Working
 -------------------------------------------------------------------------------