www/firefox: update to 96.0.3
PR: 261410
Reported by: Stefan Ehmann
Tested by: Stefan Ehmann (prior v0.3),
jbeich (PipeWire screen capture) (prior v0.8 via mail), cmt (prior v0.8 + 96.0.3 bump)
(cherry picked from commit 7b007c9d1e67ccffc09f0b60d1d039cc7f8af693)