fix(ops/gerrit-tvl): query buildkite-status endpoint and re-enable

This points our own gerrit check to the deployed buildkite-api-proxy,
updates the URL and stops sending an outdated token.

Fixes #118.

Change-Id: Ic7ace4d67a6bd05c408ac14fe988ae3fe829a49b
Reviewed-on: https://cl.snix.dev/c/snix/+/30406
Tested-by: besadii
Autosubmit: Florian Klink <flokli@flokli.de>
Reviewed-by: edef <edef@edef.eu>

ops/modules/monorepo-gerrit.nix

@@ -34,7 +34,9 @@ in
     plugins = with gerritPlugins; [
       code-owners
       oauth
-      # depot.ops.gerrit-tvl # #118
+      (depot.ops.gerrit-tvl {
+        gerrit = gerritPackage;
+      })
     ];
 
     package = gerritPackage;