build(deps): bump injector from 0.20.1 to 0.21.0 (#46)

Bumps [injector](https://github.com/alecthomas/injector) from 0.20.1 to 0.21.0.
- [Changelog](https://github.com/python-injector/injector/blob/master/CHANGES)
- [Commits](python-injector/injector@0.20.1...0.21.0)

---
updated-dependencies:
- dependency-name: injector
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]