nixosTests.ec2-config: mark as broken

This test wants to download things from the internet while building the
system. It can probably be fixed by ensuring these paths are present in
the initial nix-store.

nixos/tests/ec2.nix

@@ -108,6 +108,7 @@ in {
 
   boot-ec2-config = makeEc2Test {
     name         = "config-userdata";
+    meta.broken = true; # amazon-init wants to download from the internet while building the system
     inherit image;
     sshPublicKey = snakeOilPublicKey;