build(deps): bump smallvec from 1.4.1 to 1.4.2
Bumps [smallvec](https://github.com/servo/rust-smallvec) from 1.4.1 to 1.4.2.
- [Release notes](https://github.com/servo/rust-smallvec/releases)
- [Commits](https://github.com/servo/rust-smallvec/compare/v1.4.1...v1.4.2)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>