Backport security fixes from Firefox 115.3.1 to 115.3.0

Rather than do a whole rebase lets just cherry-pick the two commits from #42135 (closed)

assigned to @richard

added 13.0 stable label

marked this issue as related to tor-browser-build#40959 (closed)

marked this issue as related to tor-browser-build#40960 (closed)

mentioned in merge request !810 (merged)

marked this issue as related to #42135 (closed)

closed

marked this issue as related to tor-browser-build#40965 (closed)

marked this issue as related to tor-browser-build#40966 (closed)

removed the relation with tor-browser-build#40965 (closed)

removed the relation with tor-browser-build#40966 (closed)