Upgrade coverage action runtime from node20 to node24

[tim-gq]

Hi,

Thanks for maintaining this action.

The coverage/action.yml action metadata currently uses runs.using: node20. GitHub has started showing deprecation warnings for JavaScript actions that still run on Node 20, and their guidance is to migrate actions to Node 24:
https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Would you be open to updating qltysh/qlty-action/coverage to use node24?

Thanks.