tools: cleanup old ICU version-specific fixes

Our current minimum ICU is 67, so we don't need to support those anymore

PR-URL: https://github.com/nodejs/node/pull/36980


Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Beth Griggs <bgriggs@redhat.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>