feat: add customAnnotations, dnsConfig, and podLabels support

[hligit]

Why is this pull request needed and what does it do?

This PR adds several new configuration options and optimizations to the CoreDNS Helm chart:

• customAnnotations support for ClusterRole and ClusterRoleBinding: Allows users to add custom annotations to RBAC resources for better integration with tools like GitOps, policy controllers, or organizational standards.

• dnsConfig: Enables custom DNS configuration for CoreDNS pods. When dnsConfig is specified, dnsPolicy is automatically set to None as required by Kubernetes. This is useful for avoiding circular DNS dependencies or using external DNS resolvers.

• podLabels: Allows users to add custom labels specifically to pods (in addition to existing customLabels which apply to all resources). This is useful for pod-specific selectors, network policies, or monitoring configurations.

• automountServiceAccountToken: Allow setting it to false to follow Kubernetes best practices of only specifying fields when overriding defaults.

All changes are fully backward compatible with existing configurations.

Which issues (if any) are related?

None

Checklist:

• I have bumped the chart version according to versioning.
• I have updated the chart changelog with all the changes that come with this pull request according to changelog.
• Any new values are backwards compatible and/or have sensible default.
• I have signed off all my commits as required by DCO.

Changes are automatically published when merged to main. They are not published on branches.

Note on DCO

If the DCO action in the integration test fails, one or more of your commits are not signed off. Please click on the Details link next to the DCO action for instructions on how to resolve this.

[hagaibarel]

@hligit seems like the unit test install fails, probably because of helm-unittest/helm-unittest#790.

Can you please add a version pin the the lint-test workflow? It should be in https://github.com/coredns/helm/blob/master/.github/workflows/lint-test.yaml#L19-L20, and the change should be:

- name: Install helm-unittest plugin
   run: helm plugin install --version 1.0.2 https://github.com/helm-unittest/helm-unittest

[hagaibarel]

Thanks for the PR!