Accomodate new black version

Black v24.1 now puts ellipses on the same line as function definitions
in some cases, causing flake8 to emit E704. In formatting issues where
black and flake8 disagree, we side with black.

Black also does this for class definitions. There are two places in the
code base where we use `...` as the body of a class, and both are used
to mean "do nothing," as opposed to "fill this in later (ie, when
overriding)." The `pass` keyword is considered more idiomatic in no-op
situations, so that was chosen here instead of ignoring E701.

setup.cfg

@@ -54,7 +54,7 @@ exclude = .git,.tox,__pycache__,dist,venv,.venv*
 # we enforce 80 char width with `black` "loosely", so flake8 should be set to
 # not fail on up to 88 chars of width
 max-line-length = 88
-ignore = W503,W504,E203
+ignore = W503, W504, E203, B008, E704
 
 [flake8:local-plugins]
 extension =

tests/unit/test_messagepack.py

@@ -570,7 +570,8 @@ def test_unknown_envelope_fields_warn(caplog):
 def test_meta_decorator():
     # case 1: no defined internal Meta (inherited from Message)
     @meta(foo=1, bar=2)
-    class MyMessage(Message): ...
+    class MyMessage(Message):
+        pass
 
     assert MyMessage.Meta.foo == 1
     assert MyMessage.Meta.bar == 2
@@ -589,7 +590,8 @@ class Meta:
 
     # case 3: inherited internal Meta from non-Message class
     @meta(message_type="foo")
-    class MyMessage3(MyMessage2): ...
+    class MyMessage3(MyMessage2):
+        pass
 
     assert MyMessage3.Meta.foo == 1
     assert MyMessage3.Meta.bar == 3