Revert "bpf: fix is_allow_list section"

GCC was modified to use the same default section as LLVM, as such
this is no longer required.

Details:
https://github.com/gcc-mirror/gcc/commit/a0aafbc324aa90421f0ce99c6f5bbf64ed163da6

This reverts commit e8b1e9cf10.

src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.c

@@ -6,7 +6,7 @@
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 
-const volatile __u8 is_allow_list SEC(".rodata") = 0;
+const volatile __u8 is_allow_list = 0;
 
 /* Map containing the network interfaces indexes.
  * The interpretation of the map depends on the value of is_allow_list.