fix(dnsproxy): Use GOMAXPROCS and GOMEMLIMIT from Kubernetes resources

This patch implements some Go best practices for resource management.

References:
https://blog.howardjohn.info/posts/gomaxprocs/

apps/k8s01/dns/dns.yaml

@@ -31,6 +31,15 @@ spec:
             - --tls-port=853
             - --tls-crt=/etc/pki/dnsproxy/tls.crt
             - --tls-key=/etc/pki/dnsproxy/tls.key
+          env:
+            - name: GOMEMLIMIT
+              valueFrom:
+                resourceFieldRef:
+                  resource: limits.memory
+            - name: GOMAXPROCS
+              valueFrom:
+                resourceFieldRef:
+                  resource: limits.cpu
           ports:
             - containerPort: 53
               protocol: TCP