(fix) Removing Unused and Insecure Manifests for Prometheus since its integration is not supported (#1535)

We are not using these manifests or supporting this option. Therefore, they should be removed, as they are not configured to use certificates and have insecureSkipVerify: false, which promotes an insecure setup by default.

If we want enable this option then we need configure it with:

```yaml
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  labels:
    control-plane: operator-controller-controller-manager
  name: controller-manager-metrics-monitor
  namespace: system
spec:
  endpoints:
    - path: /metrics
      port: https
      scheme: https
      bearerTokenFile: /var/run/secrets/kubernetes.io/serviceaccount/token
      tlsConfig:
        insecureSkipVerify: false
        ca:
          secret:
            name: olmv1-cert
            key: ca.crt
        cert:
          secret:
            name: olmv1-cert
            key: tls.cert
        keySecret:
          name: olmv1-cert
          key: tls.key
  selector:
    matchLabels:
      control-plane: operator-controller-controller-manager
```

Author: camilamacedo86

config/base/kustomization.yaml

@@ -18,5 +18,4 @@ resources:
 - crd
 - rbac
 - manager
-# [PROMETHEUS] To enable prometheus monitor, uncomment all sections with 'PROMETHEUS'.
-#- ../prometheus
+