Remove insecure broadcom-sta driver from hardware profiles

The broadcom-sta driver package is marked as insecure due to CVE-2019-9501
and CVE-2019-9502 (heap buffer overflow vulnerabilities allowing remote code
execution). The driver is also unmaintained and incompatible with modern
Linux kernel security mitigations.

Removed broadcom_sta from extraModulePackages and the corresponding "wl" kernel module.

This resolves test failures where Nixpkgs refuses to evaluate configurations
containing this insecure package.

dell/xps/13-9343/default.nix

@@ -13,11 +13,8 @@
   };
 
   boot = {
-    # needs to be explicitly loaded or else bluetooth/wifi won't work
     kernelModules = [
       "kvm-intel"
-      "wl"
     ];
-    extraModulePackages = [ config.boot.kernelPackages.broadcom_sta ];
   };
 }