…ta type (pythonGH-103495)

a mixin must either have a __new__ method, or be a dataclass, to be interpreted as a data-type.
                    (cherry picked from commit a6f9594)

                    Co-authored-by: Ethan Furman <ethan@stoneleaf.us>

* main:
  pythongh-103479: [Enum] require __new__ to be considered a data type (pythonGH-103495)
  pythongh-103365: [Enum] STRICT boundary corrections (pythonGH-103494)
  pythonGH-103488: Use return-offset, not yield-offset. (pythonGH-103502)
  pythongh-103088: Fix test_venv error message to avoid bytes/str warning (pythonGH-103500)
  pythonGH-103082: Turn on branch events for FOR_ITER instructions. (python#103507)
  pythongh-102978: Fix mock.patch function signatures for class and staticmethod decorators (python#103228)
  pythongh-103462: Ensure SelectorSocketTransport.writelines registers a writer when data is still pending (python#103463)
  pythongh-95299: Rework test_cppext.py to not invoke setup.py directly (python#103316)

…GH-103495) (GH-103514)

a mixin must either have a __new__ method, or be a dataclass, to be interpreted as a data-type; an __init__ method is not enough (restores pre-3.11 behavior for non-dataclasses).

(cherry picked from commit a6f9594)
Co-authored-by: Ethan Furman <ethan@stoneleaf.us>