Update pytest-xdist requirement from <3 to <4 (#210)

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@1.0...v3.1.0)

---
updated-dependencies:
- dependency-name: pytest-xdist
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

setup.cfg

@@ -39,7 +39,7 @@ console_scripts =
 dev =
     pytest<8
     coverage<7
-    pytest-xdist<3
+    pytest-xdist<4
     responses==0.21.0
 docs =
     sphinx<6