cnijfilter_4_00: fix broken build

30286ebcc178aec1fb3797ba3ec88cf75feb282b updated glibc to 2.32.
This removed the deprecated <sys/sysctl.h> header, which caused a build
error on this package.
Since this header doesn't seem to be required it was removed with this
patch.

pkgs/misc/cups/drivers/cnijfilter_4_00/default.nix

···
     ./patches/cnijfilter-4.00-4-ppd.patch
     ./patches/cnijfilter-4.00-5-abi_x86_32.patch
     ./patches/cnijfilter-4.00-6-headers.patch
+    ./patches/cnijfilter-4.00-7-sysctl.patch
   ];
 
   postPatch = ''

pkgs/misc/cups/drivers/cnijfilter_4_00/patches/cnijfilter-4.00-7-sysctl.patch

···
+--- a/cnijnpr/src/cnijnpr.c
++++ b/cnijnpr/src/cnijnpr.c
+@@ -33,7 +33,6 @@
+ #include <signal.h>
+ #include <sys/ioctl.h>
+ #include <net/if.h>
+-#include <sys/sysctl.h>
+ #include <sys/types.h>
+ #include <unistd.h>
+ #include <config.h>