Update sources to pass typecheck with mypy==1.11.1

[pavoljuhas]

Description of the issue

The check/mypy script reports 97 errors when run with the latest mypy-1.11.1 (released July 30, 2024).
The CI checks are executed with mypy-1.2.0 which is 16 months old.

This issues is to track PRs to get the code in sync with mypy-1.11.1

Cirq version

1.5.0.dev at d94c457

[pavoljuhas]

Here is how to run the type check in a fresh virtual environment for Python 3.10:

pip install -r dev_tools/requirements/mypy.env.txt
pip install "mypy==1.11.1"
check/mypy