Bump pytest-xdist from 2.4.0 to 2.5.0 in /tests (signalfx#2031)

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>

tests/requirements.txt

@@ -10,7 +10,7 @@ psutil==5.8.0
 pylint==2.10.2
 pytest-html==3.1.1
 pytest-rerunfailures==10.2
-pytest-xdist==2.4.0
+pytest-xdist==2.5.0
 pytest==6.2.5
 redis==4.0.2
 requests==2.26.0