Bump execnet from 1.9.0 to 2.0.0 (#9189)

Bumps [execnet](https://github.com/pytest-dev/execnet) from 1.9.0 to 2.0.0.
- [Changelog](https://github.com/pytest-dev/execnet/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/execnet@v1.9.0...v2.0.0)

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

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

ci-constraints-requirements.txt

@@ -40,7 +40,7 @@ docutils==0.18.1
     #   sphinx-rtd-theme
 exceptiongroup==1.1.2
     # via pytest
-execnet==1.9.0
+execnet==2.0.0
     # via pytest-xdist
 filelock==3.12.2
     # via virtualenv