Bump tslib from 2.7.0 to 2.8.0

Bumps [tslib](https://github.com/Microsoft/tslib) from 2.7.0 to 2.8.0.
- [Release notes](https://github.com/Microsoft/tslib/releases)
- [Commits](microsoft/tslib@v2.7.0...v2.8.0)

---
updated-dependencies:
- dependency-name: tslib
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]