firefox: Update to 90.0

Changelog:
New

  * On Windows, updates can now be applied in the background while Firefox is
    not running.

  * Firefox for Windows now offers a new page about:third-party to help
    identify compatibility issues caused by third-party applications

  * Exceptions to HTTPS-Only mode can be managed in about:preferences#privacy

  * Print to PDF now produces working hyperlinks

  * Version 2 of Firefox??s SmartBlock feature further improves private
    browsing. Third-party Facebook scripts are blocked to prevent you from
    being tracked, but are now automatically loaded ??just in time?? if you
    decide to ??Log in with Facebook?? on any website.

Fixed

  * Various security fixes

Changed

  * The "Open Image in New Tab" context menu item now opens images and media in
    a background tab by default. Learn more

  * Most users without hardware accelerated WebRender will now be using
    software WebRender.

  * Improved software WebRender performance

  * FTP support has been removed

Enterprise

  * Various bug fixes and new policies have been implemented in the latest
    version of Firefox. See more details in the Firefox for Enterprise 90
    Release Notes.

Developer

  * Developer Information
  * Support for Private Fields (TC39 proposal, stage 3) is available in
    DevTools. The support includes: object inspection, autocompletion,
    expression evaluation, variable tooltips, and pretty printing (bug)

  * The Network panel shows a preview of HTTP requests for fonts in the
    Response tab (bug)

    Network panel font preview screenshot

Web Platform

  * Support for Fetch Metadata Request Headers, which allows web applications
    to better protect themselves and their users against various cross-origin
    threats.

  * Added the ability to use client authentication certificates stored in
    hardware tokens or in Operating System storage.

Security fixes:
#CVE-2021-29970: Use-after-free in accessibility features of a document
#CVE-2021-29971: Granted permissions only compared host; omitting scheme and
port on Android
#CVE-2021-30547: Out of bounds write in ANGLE
#CVE-2021-29972: Use of out-of-date library included use-after-free
vulnerability
#CVE-2021-29973: Password autofill on HTTP websites was enabled without user
interaction on Android
#CVE-2021-29974: HSTS errors could be overridden when network partitioning was
enabled
#CVE-2021-29975: Text message could be overlaid on top of another website
#CVE-2021-29976: Memory safety bugs fixed in Firefox 90 and Firefox ESR 78.12
#CVE-2021-29977: Memory safety bugs fixed in Firefox 90

(ryoon)