Allow self binding for generic ParamSpec

[cdce8p]

Required for python/typeshed#11662
Discussion: https://discuss.python.org/t/allow-self-binding-for-generic-paramspec/50948

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

antidote (https://github.com/Finistere/antidote)
+ tests/test_examples.py:37: error: Invalid self argument "Files" to attribute function "read" with type "Callable[[str], None]"  [misc]
+ tests/test_examples.py:37: error: Too many arguments  [call-arg]
+ tests/test_examples.py:41: error: Invalid self argument "Files" to attribute function "read" with type "Callable[[str], None]"  [misc]
+ tests/test_examples.py:41: error: Too many arguments  [call-arg]
+ tests/core/test_inject.py:517: error: Attribute function "method" with type "Callable[[], None]" does not accept self argument  [misc]
+ tests/core/test_inject.py:519: error: Invalid self argument "Conf" to attribute function "get" with type "Callable[[str], None]"  [misc]
+ tests/core/test_inject.py:519: error: Too many arguments  [call-arg]
+ tests/core/test_inject.py:522: error: Attribute function "method" with type "Callable[[], None]" does not accept self argument  [misc]
+ tests/core/test_inject.py:523: error: Invalid self argument "Conf" to attribute function "get" with type "Callable[[str], None]"  [misc]
+ tests/core/test_inject.py:523: error: Unexpected keyword argument "key"  [call-arg]

werkzeug (https://github.com/pallets/werkzeug)
+ src/werkzeug/test.py:370: error: Too many positional arguments  [misc]
+ src/werkzeug/test.py:370: error: Argument 1 has incompatible type "Mapping[str, Any]"; expected "bool"  [arg-type]

ibis (https://github.com/ibis-project/ibis)
- ibis/expr/types/relations.py:3064: error: Missing positional argument "predicates" in call to "__call__" of "_Wrapped"  [call-arg]

[cdce8p]

Primer result analysis:

antidote

They use a custom dependency injection and function overload to remove the first argument with Concatenate.
https://github.com/Finistere/antidote/blob/v2.0.0/src/antidote/core/__init__.py#L1201-L1204
While also freely mixing calling the function with self or the class name.
https://github.com/Finistere/antidote/blob/v2.0.0/tests/test_examples.py#L36-L44

werkzeug

The error comes down to this

class A:
    import json
    json_dumps = staticmethod(json.dumps)

    def func(self, j: str) -> None:
        self.json_dumps(j)

Mypy doesn't recognize that json_dumps is a @staticmethod. A workaround would be to move to the module scope and remove the staticmethod wrapper.

ibis

False positive which is removed.