chore(release): 1.0.0-alpha.8 [skip ci]

# [1.0.0-alpha.8](https://git.gitlab.arm.com/bazel/rules_download/compare/v1.0.0-alpha.7...v1.0.0-alpha.8) (2024-01-29)

### Features

* add `extension` attribute to `download_archive` ([7fb56a78](https://git.gitlab.arm.com/bazel/rules_download/commit/7fb56a78bb231ce4aea266513e708a27bba2bf6b))