chore:limit mypy when build compiled wheels

[Czaki]

The build of main currently fails with:

$ HATCH_BUILD_HOOKS_ENABLE=1 python -m build .
* Creating isolated environment: venv+pip...
* Installing packages in isolated environment:
  - hatch-vcs
  - hatchling>=1.8.0
* Getting build dependencies for sdist...
* Building sdist...
* Building wheel from sdist
* Creating isolated environment: venv+pip...
* Installing packages in isolated environment:
  - hatch-vcs
  - hatchling>=1.8.0
* Getting build dependencies for wheel...
* Installing packages in isolated environment:
  - hatch-mypyc>=0.13.0
  - msgspec; python_version < '3.14'
  - mypy
  - mypy_extensions >=0.4.2
  - pydantic!=2.10.0
  - types-attrs
* Building wheel...
Traceback (most recent call last):
  File "/home/czaki/.pyenv/versions/3.13.2/envs/psygnal/lib/python3.13/site-packages/pyproject_hooks/_in_process/_in_process.py", line 389, in <module>
    main()
    ~~~~^^
  File "/home/czaki/.pyenv/versions/3.13.2/envs/psygnal/lib/python3.13/site-packages/pyproject_hooks/_in_process/_in_process.py", line 373, in main
    json_out["return_val"] = hook(**hook_input["kwargs"])
                             ~~~~^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/czaki/.pyenv/versions/3.13.2/envs/psygnal/lib/python3.13/site-packages/pyproject_hooks/_in_process/_in_process.py", line 280, in build_wheel
    return _build_backend().build_wheel(
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        wheel_directory, config_settings, metadata_directory
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/tmp/build-env-vaxl6nxz/lib/python3.13/site-packages/hatchling/build.py", line 58, in build_wheel
    return os.path.basename(next(builder.build(directory=wheel_directory, versions=["standard"])))
                            ~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tmp/build-env-vaxl6nxz/lib/python3.13/site-packages/hatchling/builders/plugin/interface.py", line 149, in build
    build_hook.initialize(version, build_data)
    ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^
  File "/tmp/build-env-vaxl6nxz/lib/python3.13/site-packages/hatch_mypyc/plugin.py", line 338, in initialize
    raise Exception(f'Error while invoking Mypyc:\n{process.stdout.decode("utf-8")}')
Exception: Error while invoking Mypyc:
src/psygnal/_group.py:546: error: "__getattr__" not supported in class "SignalGroup" because it allows interpreted subclasses                                                                                                                                                                      
                                                                                                                                                                                                                                                                                                   

ERROR Backend subprocess exited when trying to invoke build_wheel

Looking on CI it shows that it started to fail after the mypy 1.19.0 release. This PR is to temporarily fix the build process until we understand how to fix this.

[Czaki]

It is extracted from #402

[codspeed-hq]

CodSpeed Performance Report

Merging #404 will not alter performance

_{Comparing Czaki:limit_mypyc (c931ea4) with main (abfd85e)}

Summary

✅ 67 untouched

[tlambert03]

fixing this in #405 ...