Remove `infback.c` which we don't need.
The `OF` macro was also removed so I can drop the patch where I yell
at Gentoo developers.
(cherry picked from commits e0e1f2e4a2056db1a908af75612daaaf5b129ebd
and 071499ac0d8e33e6f269437c3ce4fab52cc43f90)
Security update, fixes CVE-2022-37434 in zlib.
Only applications exposing/using `inflateGetHeader()` seem to be affected,
which is not our case, so this is not critical for Godot.
Remove duplicated copy of zlib in freetype sources to force using the updated
version in `thirdparty/zlib/`.
Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>
(cherry picked from commit 93409b8e64a9bc3c271ab4a7489b59a43bc0d048)