Fix nginx rules severity and bump opengrep 1.18.0

Author: DMarinhoCodacy

.tool_version

@@ -1 +1 @@
-1.17.0
+1.18.0

docs/codacy-rules.yaml

@@ -531,7 +531,7 @@ rules:
   - id: codacy.k8s.ingress.nginx.retirement.ingress-resource
     languages:
       - yaml
-    severity: WARNING
+    severity: ERROR
     message: >
       This Ingress is configured to use the Ingress NGINX controller
       (kubernetes.io/ingress.class: nginx or ingressClassName: nginx).
@@ -572,7 +572,7 @@ rules:
   - id: codacy.k8s.ingress.nginx.retirement.ingress-class
     languages:
       - yaml
-    severity: WARNING
+    severity: ERROR
     message: >
       This IngressClass is wired to the Ingress NGINX controller
       (spec.controller: k8s.io/ingress-nginx).
@@ -598,7 +598,7 @@ rules:
   - id: codacy.k8s.ingress.nginx.retirement.workload
     languages:
       - yaml
-    severity: WARNING
+    severity: ERROR
     message: >
       This Kubernetes resource is labelled as part of the Ingress NGINX
       controller stack (app.kubernetes.io/name: ingress-nginx).