Prepare switch to mozilla86

• #40311 (closed)
• #40312 (closed)
• #40314 (closed)
• #40315 (closed)
• #40320 (closed)
• android-components#40039 (closed)
• android-components#40040 (closed)
• android-components#40041 (closed)
• fenix#40142 (closed)
• fenix#40146 (closed)
• tor-browser-build#40217 (closed)
• tor-browser-bundle-testsuite#40017
• tor-browser-spec#40013 (closed)