build(deps): bump pkg-config from 0.3.18 to 0.3.19
Bumps [pkg-config](https://github.com/rust-lang/pkg-config-rs) from 0.3.18 to 0.3.19.
- [Release notes](https://github.com/rust-lang/pkg-config-rs/releases)
- [Changelog](https://github.com/rust-lang/pkg-config-rs/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-lang/pkg-config-rs/compare/0.3.18...0.3.19)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>