feat: ability to create releases without uploading them

[banjoh]

Summary

Adds two new flags to replicated release create so a release can be built locally and inspected (or fed into another command) without uploading it to the vendor portal:

• --no-upload: build the release locally and skip the API upload (and any promotion). Rejects --promote / --ensure-channel / --required.
• --output-dir <path>: stage the release artifacts (packaged charts + collected manifests for the .replicated config flow, or the raw release JSON payload for --yaml/--yaml-file/--chart
  flows) at the given path and preserve them after the command completes.

The two flags are orthogonal: typical usage is --no-upload --output-dir ./out to stage artifacts for inspection, while --output-dir on its own keeps a copy of what was uploaded.

Online mode is still required — the command continues to resolve the app type via the API even with --no-upload. Going fully offline is out of scope here.

Also drops an unused getToolVersion helper in cli/cmd/lint.go flagged while editing nearby code.

Refs: sc-137535

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 0ef7018. Configure here.}