fix: Add Dockerfile for digest calculation

[AndreasBergmeier6176]

Fixes: #8226

Description
inputDigest should now take Dockerfiles into account for digest calculation.

[code-review-assist]

Hi team,

I'm currently reviewing this pull request and will provide my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed:

This pull request, authored by AndreasBergmeier6176, aims to improve the digest calculation for images by incorporating Dockerfiles. The intent, as stated in the description, is to fix issue #8226.

Summary of Changes:

The core change is in pkg/skaffold/tag/input_digest.go. Specifically, lines 57-70 were modified to include Dockerfile paths in the digest calculation. The changes ensure that the following are now included:

• Paths from image.DockerArtifact.DockerfilePath
• Paths from image.KanikoArtifact.DockerfilePath
• Paths from image.CustomArtifact.Dependencies.Dockerfile.Path (if available)

These paths are appended to the srcFiles slice, which is then sorted before being used in the digest calculation. This ensures that the order of files doesn't affect the final digest.

In short: The PR enhances the accuracy of image digest calculation by considering the content of associated Dockerfiles.

---

And now, a little haiku to lighten the mood:

Dockerfile's might,
Digest now more accurate,
Builds run smoothly on.

[code-review-assist]

This change addresses issue #8226 by including Dockerfiles in the digest calculation. This is a good improvement. However, the implementation could be made more concise and robust. Also, consider adding tests to verify the changes.

[mattsanta]

Could you please update the PR title? - https://www.conventionalcommits.org/en/v1.0.0/

[mattsanta]

Thanks for addressing the PR title. Once the linters are passing we can move forward with merging.