Bump addons-linter from 8.4.0 to 9.6.0

Bumps [addons-linter](https://github.com/mozilla/addons-linter) from 8.4.0 to 9.6.0.
- [Release notes](https://github.com/mozilla/addons-linter/releases)
- [Commits](mozilla/addons-linter@8.4.0...9.6.0)

---
updated-dependencies:
- dependency-name: addons-linter
  dependency-version: 9.6.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]