Bump semver and concurrently

Removes [semver](https://github.com/npm/node-semver). It's no longer used after updating ancestor dependency [concurrently](https://github.com/open-cli-tools/concurrently). These dependencies need to be updated together.


Removes `semver`

Updates `concurrently` from 6.0.0 to 6.5.1
- [Release notes](https://github.com/open-cli-tools/concurrently/releases)
- [Commits](open-cli-tools/concurrently@v6.0.0...v6.5.1)

---
updated-dependencies:
- dependency-name: semver
  dependency-type: indirect
- dependency-name: concurrently
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>