deps: ICU 61.1 bump

- Update to released ICU 61.1, including:
  - CLDR 33 (many new languages and data improvements)
  - Many small API additions, improvements, and bug fixes
  - note: 'icu::' namespace is no longer used by default
   (Necessated https://github.com/nodejs/node/pull/18667 )

PR-URL: https://github.com/nodejs/node/pull/19621


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>