Enhance Security of This Helm Chart Based on Pod Security Standards

[CASL0]

Hi, I've created a pull request that enhances pod security.
This pull request introduces a series of security enhancements to the coturn chart, aligning it with the latest pod security standards.

These changes are designed to strengthen the security posture of the applications deployed using this chart, mitigating potential vulnerabilities and ensuring compliance with best practices in Kubernetes security.

I fixed the chart to ensure full compliance with the Kubernetes Pod Security Standards Restricted policy.
This means that you can deploy the chart on a namespace as shown in the following manifest.

apiVersion: v1
kind: Namespace
metadata:
  name: my-ns
  labels:
    pod-security.kubernetes.io/enforce: restricted

Could someone please review it and provide feedback?

[jessebot]

Awesome, thanks for this! :)