meta: update collaborator email in README

Update email for Shelley Vohr to correspond to what is specified in
.mailmap and what is used in more recently authored commits.

PR-URL: #39521
Reviewed-By: Zeyu Yang <himself65@outlook.com>
Reviewed-By: Ujjwal Sharma <ryzokuken@disroot.org>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: Trott

README.md

@@ -168,7 +168,7 @@ For information about the governance of the Node.js project, see
 * [cjihrig](https://github.com/cjihrig) -
 **Colin Ihrig** <cjihrig@gmail.com> (he/him)
 * [codebytere](https://github.com/codebytere) -
-**Shelley Vohr** <codebytere@gmail.com> (she/her)
+**Shelley Vohr** <shelley.vohr@gmail.com> (she/her)
 * [danbev](https://github.com/danbev) -
 **Daniel Bevenius** <daniel.bevenius@gmail.com> (he/him)
 * [danielleadams](https://github.com/danielleadams) -
@@ -288,7 +288,7 @@ For information about the governance of the Node.js project, see
 * [cjihrig](https://github.com/cjihrig) -
 **Colin Ihrig** <cjihrig@gmail.com> (he/him)
 * [codebytere](https://github.com/codebytere) -
-**Shelley Vohr** <codebytere@gmail.com> (she/her)
+**Shelley Vohr** <shelley.vohr@gmail.com> (she/her)
 * [danbev](https://github.com/danbev) -
 **Daniel Bevenius** <daniel.bevenius@gmail.com> (he/him)
 * [danielleadams](https://github.com/danielleadams) -