update changelog, warning msg and warning inherit

changelog/7337.improvement.rst

@@ -1 +1 @@
-Warns for test functions that return non-None. Now in `pytest_pyfunc_call` after the `async_warn_and_skip` it will check for if the return is something other than None.
+Warns for test functions that return non-None.

src/_pytest/python.py

@@ -197,9 +197,8 @@ def pytest_pyfunc_call(pyfuncitem: "Function") -> Optional[object]:
     elif result is not None:
         warnings.warn(
             PytestReturnNotNoneWarning(
-                "Test function returning {result}, do you mean to use `assert` instead or `return`?".format(
-                    result=result
-                )
+                f"Expected None, but the test returned {result!r}, which will be an error in a "
+                "future version of Pytest.  Did you mean to use `assert` instead of `return`?"
             )
         )
     return True

src/_pytest/warning_types.py

@@ -42,13 +42,6 @@ class PytestCollectionWarning(PytestWarning):
     __module__ = "pytest"
 
 
-@final
-class PytestReturnNotNoneWarning(PytestWarning):
-    """Warning emitted when a test function is returning value other than None."""
-
-    __module__ = "pytest"
-
-
 class PytestDeprecationWarning(PytestWarning, DeprecationWarning):
     """Warning class for features that will be removed in a future version."""
 
@@ -62,6 +55,13 @@ class PytestRemovedIn8Warning(PytestDeprecationWarning):
     __module__ = "pytest"
 
 
+@final
+class PytestReturnNotNoneWarning(PytestDeprecationWarning):
+    """Warning emitted when a test function is returning value other than None."""
+
+    __module__ = "pytest"
+
+
 @final
 class PytestExperimentalApiWarning(PytestWarning, FutureWarning):
     """Warning category used to denote experiments in pytest.