Bump jupyter-client from 6.1.12 to 7.0.2 in /extra_requirements

Bumps [jupyter-client](https://github.com/jupyter/jupyter_client) from 6.1.12 to 7.0.2.
- [Release notes](https://github.com/jupyter/jupyter_client/releases)
- [Changelog](https://github.com/jupyter/jupyter_client/blob/master/CHANGELOG.md)
- [Commits](jupyter/jupyter_client@6.1.12...v7.0.2)

---
updated-dependencies:
- dependency-name: jupyter-client
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

extra_requirements/requirements-tests.txt

@@ -11,7 +11,7 @@ flake8==3.9.2
 holoviews==1.14.5
 ipywidgets==7.6.3
 hypothesis==6.17.4
-jupyter-client==6.1.12                          # for ipywidgets
+jupyter-client==7.0.2                          # for ipywidgets
 matplotlib==3.4.3
 multihist==0.6.4
 npshmex==0.2.1                                  # Strax dependency