Pin pytest 8 to version 8.0.1

- avoids problem in 8.0.2, see
   pytest-dev/pytest#1203

Author: mrbean-bremen

tox.ini

@@ -12,7 +12,7 @@ deps =
     pytest624: pytest>=6.2.4,<6.3
     pytest70: pytest>=7.0,<7.1
     pytest74: pytest>=7.3,<8.0
-    pytest80: pytest>=8.0,<9.0
+    pytest80: pytest==8.0.1
     pytest-cov<2.10
     pytest{50,54}: pytest-xdist<2.0.0
     pytest{60,62,624,70,74,80}: pytest-xdist