Bump xdist.

Author: ionelmc

tox.ini

@@ -41,7 +41,7 @@ usedevelop =
     nocov: false
 deps =
     pytest-instafail==0.4.2
-    {py37,py38,py39,pypy3}-xdist: pytest-xdist==2.1.0
+    xdist: pytest-xdist==2.5.0
     pytest71: pytest==7.1.3
     pytest72: pytest==7.2.0
     cover: pytest-cov