Bump browserslist from 4.16.3 to 4.21.7 in /monitoring/web (#10)

Bumps [browserslist](https://github.com/browserslist/browserslist) from 4.16.3 to 4.21.7.
- [Changelog](https://github.com/browserslist/browserslist/blob/main/CHANGELOG.md)
- [Commits](browserslist/browserslist@4.16.3...4.21.7)

---
updated-dependencies:
- dependency-name: browserslist
  dependency-type: indirect
...

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