Improve the release workflow to not edit enum values in values.yaml

[salonichf5]

Describe the bug
The release workflow needs to be improved to not edit enum fields in values.yaml

To Reproduce
Steps to reproduce the behavior:

1. Run the release workflow
2. View the PR, check the values.yaml has correct enum values for images of NGF and NGINX and verify if you see the error in logs enum values cannot be same

Expected behavior
When we run the release workflow, ensure that none of the enum values are replaced when we run the Find and Replace jobs in release workflow.

Your environment

• Version of the NGINX Gateway Fabric - 1.5.0
• Version of Kubernetes - 1.25+
• Kubernetes platform (e.g. Mini-kube or GCP) - KIND
• Details on how you expose the NGINX Gateway Fabric Pod (e.g. Service of type LoadBalancer or port-forward) - N/A
• Logs of NGINX container: kubectl -n nginx-gateway logs -l app=nginx-gateway -c nginx
• NGINX Configuration: kubectl -n nginx-gateway exec <gateway-pod> -c nginx -- nginx -T

Additional context

• For example: ImagePullPolicy is changed from Always to IfNotPresent