Update assets instead of removing and adding again

[eine]

Refs:

• remove assets with the same label actions/upload-release-asset#22
• https://octokit.github.io/rest.js/v18#repos-update-release-asset
• https://pygithub.readthedocs.io/en/latest/github_objects/GitReleaseAsset.html?highlight=asset#github.GitReleaseAsset.GitReleaseAsset.update_asset