src: remove accidentally added src/txt

PR-URL: https://github.com/nodejs/node/pull/23273
Refs: https://github.com/nodejs/node/pull/23072


Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Gus Caplan <me@gus.host>