nixosTests.caddy: migrate to runTest (#395444)

nixos/tests/all-tests.nix

@@ -270,7 +270,7 @@ in
   buildbot = runTest ./buildbot.nix;
   buildkite-agents = handleTest ./buildkite-agents.nix { };
   c2fmzq = handleTest ./c2fmzq.nix { };
-  caddy = handleTest ./caddy.nix { };
+  caddy = runTest ./caddy.nix;
   cadvisor = handleTestOn [ "x86_64-linux" ] ./cadvisor.nix { };
   cage = handleTest ./cage.nix { };
   cagebreak = handleTest ./cagebreak.nix { };

nixos/tests/caddy.nix

@@ -1,6 +1,5 @@
-import ./make-test-python.nix (
-  { pkgs, ... }:
-  {
+{ pkgs, ... }:
+{
   name = "caddy";
   meta = with pkgs.lib.maintainers; {
     maintainers = [
@@ -151,5 +150,4 @@ import ./make-test-python.nix (
           webserver.wait_for_open_port(80)
           webserver.succeed("curl http://localhost | grep caddy")
     '';
-  }
-)
+}