www/firefox-esr: update to 140.2 (rc1)

While here, chase WWW location move as advertised by upstream.

Release Notes (soon):

https://www.firefox.com/en-US/firefox/140.2.0/releasenotes/

(cherry picked from commit aaf058292b96d5a07eaad6ce1d3aee44e1f5ce19)