wireless-regdb: add crda to tests

This will make it easier to catch bugs like
https://github.com/NixOS/nixpkgs/pull/286012#issuecomment-1929238512 in
future.

pkgs/data/misc/wireless-regdb/default.nix

@@ -1,4 +1,4 @@
-{ lib, stdenvNoCC, fetchurl, directoryListingUpdater }:
+{ lib, stdenvNoCC, fetchurl, directoryListingUpdater, crda }:
 
 stdenvNoCC.mkDerivation rec {
   pname = "wireless-regdb";
@@ -16,7 +16,12 @@ stdenvNoCC.mkDerivation rec {
     "PREFIX="
   ];
 
-  passthru.updateScript = directoryListingUpdater { };
+  passthru = {
+    tests = {
+      inherit crda; # validate data base signature
+    };
+    updateScript = directoryListingUpdater { };
+  };
 
   meta = with lib; {
     description = "Wireless regulatory database for CRDA";