Fix and simplify tox.ini

Author: Cito

tox.ini

@@ -11,7 +11,7 @@ python =
     3.10: py310
     3.11: py311
     3.12: py312
-    pypy3: pypy9
+    pypy3: pypy39
     pypy3.9: pypy39
     pypy3.10: pypy310
 
@@ -50,5 +50,5 @@ deps =
 commands =
     # to also run the time-consuming tests: tox -e py311 -- --run-slow
     # to run the benchmarks: tox -e py311 -- -k benchmarks --benchmark-enable
-    py37,py38,py39,py310,py311,pypy39,pypy310: pytest tests {posargs}
+    py3{7,8,9,10,11},pypy3{9,10}: pytest tests {posargs}
     py312: pytest tests {posargs: --cov-report=term-missing --cov=graphql --cov=tests --cov-fail-under=100}