Improve kpt version resolution in setup-go-kpt composite action

[aravindtga]

Description

What changed:

• Resolve the kpt version with go mod edit -json (parsing the require block) instead of go list -m, reading the version directly from the target go.mod without resolving the full module graph. This mirrors the approach already used by the sibling check-go-mod-replace action.
  • Add an optional kpt-version-file input so callers can resolve the kpt version from a go.mod different from the one used for Go setup. It defaults to go-version-file, preserving existing behaviour.
• Surface fallback conditions with ::warning:: annotations (missing version file, or github.com/kptdev/kpt not found in the require block) instead of a silently swallowed message, and log the resolved kpt version.
  • Harden the resolution step with set -euo pipefail and a file-existence check before use.
  • Update the default kpt-fallback-version from v1.0.0-beta.65 to v1.0.0 (the current latest kpt release) so the safety-net default is not stale.

Why it's needed:

• A recent krm-functions-catalog e2e-ci run showed the previous go list -m ... 2>/dev/null logic returning an empty version and silently falling back, then installing a kpt binary that did not match the version the e2e module was built against.

How it works:

• go mod edit -json | jq reads the declared version straight from the require block of the resolved version file (kpt-version-file if set, otherwise go-version-file), making resolution deterministic and authoritative.
  • If the file is missing, or kpt is not a direct requirement, a ::warning:: annotation is emitted and the action falls back to kpt-fallback-version.
• This action is consumed by porch, krm-functions-catalog, and krm-functions-sdk. The change is backward compatible: all install-kpt: "false" call sites are unaffected, and every install call site resolves to the same version as before (porch go.mod -> v1.0.0-beta.67, krm-functions-catalog tests/e2etest/go.mod -> v1.0.0-beta.65.1). The new input is opt-in with a behaviour-preserving default, and the fallback default change is inert for current consumers because the fallback path is not exercised when kpt is a direct dependency.

Type of Change

• Bug fix
• New feature
• Enhancement
• Refactor
• Documentation
• Tests
• Other: ________

Checklist

• Code follows project style guidelines
• Self-reviewed changes
• Tests added/updated
• Documentation added/updated
• All tests and gating checks pass

AI Disclosure

• I have used AI in the creation of this PR.

If so, please describe how:
- Kiro to analyse the composite action and its consumers, verify version resolution behaviour, and draft the PR changes and PR description.

[netlify]

✅ Deploy Preview for kptdocs ready!

Name	Link
🔨 Latest commit	f6b70e2
🔍 Latest deploy log	https://app.netlify.com/projects/kptdocs/deploys/6a98018b27ad4f00080d4ac1
😎 Deploy Preview	https://deploy-preview-4730--kptdocs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.
🤖 Make changes	Run an agent on this branch

---

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