Bump pytest-xdist from 2.4.0 to 2.5.0 (AtsushiSakai#597)

Bumps [pytest-xdist](https://github.com/pytest-dev/pytest-xdist) from 2.4.0 to 2.5.0.
- [Release notes](https://github.com/pytest-dev/pytest-xdist/releases)
- [Changelog](https://github.com/pytest-dev/pytest-xdist/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-xdist@v2.4.0...v2.5.0)

---
updated-dependencies:
- dependency-name: pytest-xdist
  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]

requirements.txt

@@ -4,7 +4,7 @@ pandas == 1.3.4
 matplotlib == 3.5.0
 cvxpy == 1.1.17
 pytest == 6.2.5 # For unit test
-pytest-xdist == 2.4.0 # For unit test
+pytest-xdist == 2.5.0 # For unit test
 sphinx < 4.0 # For sphinx documentation
 sphinx_rtd_theme == 1.0.0
 IPython == 7.30.1 # For sphinx documentation