doc: move tunniclm to Emeritus

tunniclm indicated that it would be a good idea to move them to
Collaborator Emeritus for now. This commit makes that change in the
README.md file.

PR-URL: #20533
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

Author: Trott

README.md

@@ -514,8 +514,6 @@ For more information about the governance of the Node.js project, see
 **Trivikram Kamat** <trivikr.dev@gmail.com>
 * [Trott](https://github.com/Trott) -
 **Rich Trott** <rtrott@gmail.com> (he/him)
-* [tunniclm](https://github.com/tunniclm) -
-**Mike Tunnicliffe** <m.j.tunnicliffe@gmail.com>
 * [vdeturckheim](https://github.com/vdeturckheim) -
 **Vladimir de Turckheim** <vlad2t@hotmail.com> (he/him)
 * [vkurchatkin](https://github.com/vkurchatkin) -
@@ -559,6 +557,8 @@ For more information about the governance of the Node.js project, see
 **Alex Kocharin** <alex@kocharin.ru>
 * [tellnes](https://github.com/tellnes) -
 **Christian Tellnes** <christian@tellnes.no>
+* [tunniclm](https://github.com/tunniclm) -
+**Mike Tunnicliffe** <m.j.tunnicliffe@gmail.com>
 
 Collaborators follow the [COLLABORATOR_GUIDE.md](./COLLABORATOR_GUIDE.md) in
 maintaining the Node.js project.