Upate Webhooks after Upgrade

[Neumann-Nils]

Description

This PR reapplies the webhook installation script after an upgrade (not just an install). This allows it to make changes to the webhook without deleting and installing Karydia, but rather just upgrading it.

Checklist

Before submitting this PR, please make sure:

• [x] your code builds clean with make
• [x] your code lets succeed unit tests with make test
• [x] your code lets succeed integration tests

[Neumann-Nils]

How to test that the webhook is upgraded with helm upgrade:

1. Install Karydia:

   kubectl create namespace karydia
   helm install karydia ./install/charts --namespace karydia

2. Check the configuration of the mutating/validating webhook:

   
   kubectl describe MutatingWebhookConfiguration karydia-webhook
   kubectl describe ValidatingWebhookConfiguration karydia-webhook

[...] Namespace Selector: Match Expressions: Key: app Operator: NotIn Values: karydia [...]

3. Make changes to e.g. the `values.yaml` file:
```diff
     exclusionNamespaceLabels:
-     - key: "app"
-       values:
-       - "karydia"
+     - key: "exclude"
+       values:
+       - "true"

4. 
   kubectl describe MutatingWebhookConfiguration karydia-webhook
   kubectl describe ValidatingWebhookConfiguration karydia-webhook

[...] Namespace Selector: Match Expressions: Key: exclude Operator: NotIn Values: true [...]