/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/calendar-timezones@mozilla.org is in xul-ext-calendar-timezones 1.3+build1-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/../../../xul-ext/calendar-timezones