build(deps): bump arc-swap from 0.4.7 to 0.4.8
Bumps [arc-swap](https://github.com/vorner/arc-swap) from 0.4.7 to 0.4.8.
- [Release notes](https://github.com/vorner/arc-swap/releases)
- [Changelog](https://github.com/vorner/arc-swap/blob/v0.4.8/CHANGELOG.md)
- [Commits](https://github.com/vorner/arc-swap/compare/v0.4.7...v0.4.8)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>