linux_5_4_hardened: mark as broken

Smoketest fails with

    machine # [    3.785769] systemd[1]: dev-hugepages.mount: Failed to spawn executor: Argument list too long
    machine # [    3.788689] systemd[1]: dev-hugepages.mount: Failed to spawn 'mount' task: Argument list too long
    machine # [    3.790100] systemd[1]: dev-hugepages.mount: Failed with result 'resources'.
    machine # [    3.791572] systemd[1]: Failed to mount Huge Pages File System.

pkgs/top-level/linux-kernels.nix

@@ -26,6 +26,10 @@ let
     linux = kernel;
   };
 
+  markBroken = drv: drv.overrideAttrs ({ meta ? {}, ... }: {
+    meta = meta // { broken = true; };
+  });
+
   # Hardened Linux
   hardenedKernelFor = kernel': overrides:
     let
@@ -259,10 +263,10 @@ in {
 
     linux_hardened = hardenedKernelFor packageAliases.linux_default.kernel { };
 
-    linux_5_4_hardened = hardenedKernelFor kernels.linux_5_4 {
+    linux_5_4_hardened = markBroken (hardenedKernelFor kernels.linux_5_4 {
       stdenv = gcc10Stdenv;
       buildPackages = buildPackages // { stdenv = buildPackages.gcc10Stdenv; };
-    };
+    });
     linux_5_10_hardened = hardenedKernelFor kernels.linux_5_10 { };
     linux_5_15_hardened = hardenedKernelFor kernels.linux_5_15 { };
     linux_6_1_hardened = hardenedKernelFor kernels.linux_6_1 { };