firefox: import upstream bugfixes
1 https://bugzilla.mozilla.org/show_bug.cgi?id=1694670
"Linux startup crash in [@ qcms_data_create_rgb_with_gamma]" crash on startup when loading certain ICC profiles
2 https://bugzilla.mozilla.org/show_bug.cgi?id=1694699
"Investigate tabs API regression in Firefox 86" regression causing loss of tabs from tab groups
PR: 253886 ([2])
Reported by: Hans Petter Selasky [1], Graham Perrin [2]
MFH: 2021Q1