chore: snapcore/action-build deprecation warning — snapcraft pack

[q-soriarty]

Problem

The Snap publish workflow produces a deprecation warning:

Running snapcraft without a command will not be possible in future releases. Use 'snapcraft pack' instead.

This comes from snapcore/action-build@v1 which calls snapcraft without the pack subcommand.

Impact

Non-blocking now. Will break when Snapcraft removes the implicit pack behavior (likely Snapcraft 9.x).

Blocked on

• snapcore/action-build upstream — no v2 release or fix available yet
• Neither snapcore/action-build nor canonical/action-build have released a version that uses snapcraft pack

Workaround options

1. Wait for upstream fix
2. Replace action with manual snapcraft pack call in the workflow
3. Pin snapcraft version to avoid future breakage

References

• https://github.com/snapcore/action-build
• https://github.com/canonical/action-build