Local tag lister for semantic version constraint matching

[mozesl-nokia]

Fixes #4457

• TagResolver now accepts a slice of tag listers.
• Added LocalLister which does a docker/podman/nerdctl image ls with a filter to search for tags locally.
• Moved the lister code to container_utils.go
• Improved coverage a little bit

Might need doc updates, let's see if Dosu finds anything.

[netlify]

✅ Deploy Preview for kptdocs ready!

Name	Link
🔨 Latest commit	af03975
🔍 Latest deploy log	https://app.netlify.com/projects/kptdocs/deploys/69dca902f095da000780d5f7
😎 Deploy Preview	https://deploy-preview-4458--kptdocs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[Copilot]

Pull request overview

This PR implements local tag listing for semantic version constraint matching, addressing issue #4457. It allows kpt to search for tags in local container images first before attempting to query remote registries, reducing unnecessary network calls and enabling testing with in-progress function versions.

Changes:

• Modified TagResolver to accept a slice of TagListers instead of a single lister, enabling fallback from local to remote tag sources
• Added LocalLister implementation that uses container CLI tools (docker/podman/nerdctl) to list local OCI image tags
• Moved RegClientLister from container.go to a new container_utils.go file
• Updated tag resolution logic to iterate through listers, logging errors and continuing to the next lister on failure
• Added Name() method to the TagLister interface
• Updated tests to reflect the new architecture and added comprehensive tests for the abbrevSlice function
• Minor style improvements: removed build tags and loop variable shadowing from container_test.go

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
internal/fnruntime/tag_resolution.go	Modified TagResolver to use a slice of listers and updated the resolution logic to check each lister in order
internal/fnruntime/tag_resolution_test.go	Updated tests to use the new Listers field and added comprehensive tests for abbrevSlice; updated error expectations
internal/fnruntime/container.go	Removed RegClientLister code, removed regclientref import, updated to use new Listers slice
internal/fnruntime/container_utils.go	New file containing RegClientLister (moved) and LocalLister implementation with helper function linesToSlice
internal/fnruntime/container_test.go	Removed build tags and cleaned up loop variable shadowing
pkg/test/runner/runner.go	Removed extra blank line

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.