Update pytest-xdist requirement from ~=3.7 to ~=3.8 (#10451)

Updates the requirements on [pytest-xdist](https://github.com/pytest-dev/pytest-xdist) to permit the latest version.
- [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@v3.7.0...v3.8.0)

---
updated-dependencies:
- dependency-name: pytest-xdist
  dependency-version: 3.8.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements_test.txt

@@ -3,6 +3,6 @@ coverage~=7.9
 tbump~=6.11.0
 contributors-txt>=1.0.0
 pytest-cov~=6.2
-pytest-xdist~=3.7
+pytest-xdist~=3.8
 six
 tox>=3