nixos/security/wrappers: don't force PIE hardening (#259509)

PIE causes problems with static binaries on ARM (see 76552e9). It is
enabled by default on other platforms anyway when musl is used, so we
don't need to specify it manually.

nixos/modules/security/wrappers/wrapper.nix

···
   name = "security-wrapper";
   buildInputs = [ linuxHeaders ];
   dontUnpack = true;
-  hardeningEnable = [ "pie" ];
   CFLAGS = [
     ''-DSOURCE_PROG="${sourceProg}"''
   ] ++ (if debug then [