feat: add automatic Helm chart support detection

[swade1987]

Description

This PR addresses an issue where the kustomize-diff action fails when processing kustomization files that include Helm charts.

Problem

When a kustomization.yaml file includes the helmCharts field, the action would fail with the following error:

`: must specify --enable-helm
This happens because Kustomize requires an explicit --enable-helm flag when building configurations that include Helm charts.

Solution

This PR adds automatic detection of Helm charts in kustomization files by:

1. Checking for the presence of helmCharts: in each kustomization file
2. Automatically adding the --enable-helm flag when needed
3. Preserving the original behaviour for kustomization files that don't use Helm charts

Benefits

1. Zero configuration: Users don't need to set any additional parameters
2. Backwards compatible: No changes required for existing workflows
3. Future proof: Works with mixed environments where only some kustomization files use Helm charts
4. Transparent: Adds debug logging when Helm support is enabled

This change makes the action more robust and able to handle a wider variety of Kustomize configurations without user intervention.

How has this been tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s

Towards/Closes

Closes #12

[swade1987]

🎉 This PR is included in version 0.4.0 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀