mypy 2.0.0 not supported in all packages

https://pypi.org/project/mypy/2.0.0/ was released yesterday on May 6. We see the following failure in `google-cloud-bigtable`

```
nox > Running session mypy
nox > Creating virtual environment (virtualenv) using python3.14 in .nox/mypy
nox > python -m pip install -e .
nox > python -m pip install mypy types-setuptools types-protobuf types-mock types-requests
nox > python -m pip install google-cloud-testutils
nox > mypy -p google.cloud.bigtable.data
google/cloud/bigtable/data/execute_query/_byte_cursor.py:109: error: Argument 1 to "append" of "list" has incompatible type "memoryview[int]"; expected "bytes" [arg-type]
```

This bug tracks updating `google-cloud-bigtable` to use mypy 2.0.0