Bump y18n from 4.0.0 to 4.0.1 in /firestore/solution-sharded-timestamp (#217)

Bumps [y18n](https://github.com/yargs/y18n) from 4.0.0 to 4.0.1.
- [Release notes](https://github.com/yargs/y18n/releases)
- [Changelog](https://github.com/yargs/y18n/blob/master/CHANGELOG.md)
- [Commits](https://github.com/yargs/y18n/commits)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]