chore(tox): add comment why we specify tests for pypy envs

Author: danceratopz

tox.ini

@@ -28,6 +28,7 @@ commands =
         src
 
 [testenv:tests_pytest_pypy3]
+# overwrite default groups (dev) to avoid installing optimized in tox envs using pypy
 dependency_groups =
     test
 passenv =
@@ -68,6 +69,7 @@ commands =
         tests
 
 [testenv:pypy3]
+# see comment for tests_pytest_pypy3
 dependency_groups =
     test
 passenv =