doc: move Italo A. Casas to Release Emeritus

Have confirmed 1:1 that they are ok with this.

PR-URL: https://github.com/nodejs/node/pull/21315


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Italo A. Casas <me@italoacasas.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>