fix: drop bogus letsencrypt certResolver from dharma IngressRoute

Traefik has no certificate resolver named 'letsencrypt' configured (this
cluster terminates TLS at Cloudflare and uses Traefik's default cert via
the websecure entrypoint, matching every other neuron-prod IngressRoute).

The invalid certResolver caused Traefik to refuse the router with:
  ERR Router uses a nonexistent certificate resolver
    certificateResolver=letsencrypt routerName=neuron-prod-dharma-...

so requests to dharma.neurontechnologies.ai/health surfaced as 502 from
Cloudflare even though the dharma pod was healthy on :8765.

servers/legion/k8s/neuron-technologies/dharma/ingressroute.yaml

@@ -14,5 +14,6 @@ spec:
       services:
         - name: dharma
           port: 8765
-  tls:
-    certResolver: letsencrypt
+  # TLS terminates at Cloudflare; tunnel reaches Traefik with noTLSVerify.
+  # Traefik websecure entrypoint has its own default cert (no resolver
+  # configured in this cluster), matching every other neuron-prod IngressRoute.