chore: address goreleaser deprecation notices

[xnyo]

Updates the goreleaser config file to address deprecation notices

    • DEPRECATED: snapshot.name_template should not be used anymore, check https://goreleaser.com/deprecations#snapshotname_template for more info
    • DEPRECATED: archives.format should not be used anymore, check https://goreleaser.com/deprecations#archivesformat for more info
    • DEPRECATED: archives.format_overrides.format should not be used anymore, check https://goreleaser.com/deprecations#archivesformat_overridesformat for more info

For example see: https://github.com/grafana/plugin-validator/actions/runs/19131963065/job/54674667842#step:8:25

Docs for deprecation notices:

• https://goreleaser.com/deprecations/#snapshotname_template
• https://goreleaser.com/deprecations/#archivesformat
• https://goreleaser.com/deprecations/#archivesformat_overridesformat