Importing fails with OSError from `getpass.getuser` on Python 3.13+

[pandaxtc]

Describe the bug

As of Python 3.13, getpass.getuser now raises OSError on any failures instead of KeyError. This means that this line doesn't work anymore, and the library crashes on import.

PyMySQL fixed this issue in this commit: PyMySQL/PyMySQL@a1ac823

To Reproduce

1. Import aiomysql inside a Docker container with Python 3.13+ with the UID set to something without a username.
2. Observe crash.

Expected behavior

It does not crash.

Logs/tracebacks

Traceback (most recent call last):
  File "/usr/local/lib/python3.13/getpass.py", line 173, in getuser
    return pwd.getpwuid(os.getuid())[0]
           ~~~~~~~~~~~~^^^^^^^^^^^^^
KeyError: 'getpwuid(): uid not found: 8459'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/app/lib/python3.13/site-packages/package/__main__.py", line 1, in <module>
    from package import main
  File "/app/lib/python3.13/site-packages/package/esc_dl.py", line 17, in <module>
    import aiomysql
  File "/app/lib/python3.13/site-packages/aiomysql/__init__.py", line 32, in <module>
    from .connection import Connection, connect
  File "/app/lib/python3.13/site-packages/aiomysql/connection.py", line 42, in <module>
    DEFAULT_USER = getpass.getuser()
  File "/usr/local/lib/python3.13/getpass.py", line 175, in getuser
    raise OSError('No username set in the environment') from e
OSError: No username set in the environment

Python Version

$ python --version
Python 3.13.9

aiomysql Version

$ python -m pip show aiomysql
Name: aiomysql
Version: 0.3.2
Location: /package/.venv/lib/python3.13/site-packages
Requires: pymysql
Required-by: ...

PyMySQL Version

$ python -m pip show PyMySQL
Name: pymysql
Version: 1.1.2
Location: /package/.venv/lib/python3.13/site-packages
Requires:
Required-by: aiomysql

SQLAlchemy Version

$ python -m pip show sqlalchemy
N/A

OS

Linux 6.8.0-84-generic #84-Ubuntu SMP PREEMPT_DYNAMIC Fri Sep 5 22:36:38 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Database type and version

SELECT VERSION();
N/A

Additional context

No response

Code of Conduct

• I agree to follow the aio-libs Code of Conduct