creating multiple pools with the same spec should be forbidden

[bavarianbidi]

What steps did you take and what happened?

Creating two pool objects with different names (but same spec) will result in one pool on garm-side.
On Kubernetes booth pools will have the same status.id

apiVersion: garm-operator.mercedes-benz.com/v1alpha1
kind: Pool
metadata:
  name: openstack-default-runner-os01
  namespace: garm-prod
spec:
  githubScopeRef:
    apiGroup: garm-operator.mercedes-benz.com
    kind: Enterprise
    name: mercedes-benz-group-ag
  enabled: true
  extraSpecs: '{"garm_image_type":"runner-default","garm_stage":"prod"}'
  flavor: m1.large
  githubRunnerGroup: ""
  imageName: runner-roadkit
  maxRunners: 10
  minIdleRunners: 1
  osArch: amd64
  osType: linux
  providerName: os01.fra-prod3
  runnerBootstrapTimeout: 20
  runnerPrefix: "road-runner-os013"
  tags:
  - ubuntu
---
apiVersion: garm-operator.mercedes-benz.com/v1alpha1
kind: Pool
metadata:
  name: openstack-default-runner-os02
  namespace: garm-prod
spec:
  githubScopeRef:
    apiGroup: garm-operator.mercedes-benz.com
    kind: Enterprise
    name: mercedes-benz-group-ag
  enabled: true
  extraSpecs: '{"garm_image_type":"runner-default","garm_stage":"prod"}'
  flavor: m1.large
  githubRunnerGroup: ""
  imageName: runner-roadkit
  maxRunners: 10
  minIdleRunners: 1
  osArch: amd64
  osType: linux
  providerName: os01.fra-prod3
  runnerBootstrapTimeout: 20
  runnerPrefix: "road-runner-os013"
  tags:
  - ubuntu

What did you expect to happen?

pool webhook should reject the creation of objects with the same spec if already one object exist.

The current implementation already forse this behavior but doesn't block the second creation request (https://github.com/mercedes-benz/garm-operator/blob/main/api/v1alpha1/pool_webhook.go#L71-L82)

garm version

v0.1.3

garm-operator version

v0.1.0

Kubernetes version

Kubernetes 1.25.5

Anything else you would like to add?

No response