chore: lower requires-python to >=3.12 for broader compatibility

[Nwokike]

The current requires-python = ">=3.13" constraint is overly restrictive. The codebase uses no Python 3.13-specific features — the highest actual requirement is Python 3.11 (hashlib.file_digest(), datetime.timezone.utc).

Lowering to >=3.12 enables:

• Use on platforms where Python 3.13 isn't available (e.g., Android via Chaquopy, which supports up to 3.12)
• Broader CI/CD compatibility
• Earlier adoption in constrained environments

All existing tests should pass on 3.12. No code changes were needed — the requirement was purely a metadata version pin.

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[teeler]

All existing tests should pass on 3.12

I'd love for you to send me a screenshot or a text snippet that demonstrates this

Also please read this --> https://github.com/googlecolab/google-colab-cli/blob/main/CONTRIBUTING.md

I'm OK with this for the moment considering it's tiny, but if you could run the tests so we can be sure that would convince me.

[Nwokike]

Hi @teeler,
Thank you for taking a look at this. I just read through CONTRIBUTING.md, so I really appreciate you being open to considering this change.
As requested, all tests pass successfully on Python 3.12. You can verify the full GitHub Actions run here:
https://github.com/Nwokike/google-colab-cli/actions/runs/27303211428/job/80654135060
This is the environment snippet from that run:

Run uv run --python 3.12 pytest
  uv run --python 3.12 pytest
  shell: /usr/bin/bash -e {0}
Using CPython 3.12.13 interpreter at: /opt/hostedtoolcache/Python/3.12.13/x64/bin/python3.12
Creating virtual environment at: .venv
   Building google-colab-cli @ file:///home/runner/work/google-colab-cli/google-colab-cli
Installed 57 packages in 33ms
============================= test session starts ==============================
platform linux -- Python 3.12.13, pytest-9.0.2, pluggy-1.6.0
rootdir: /home/runner/work/google-colab-cli/google-colab-cli
configfile: pyproject.toml
plugins: mock-3.15.1, cov-7.0.0
collected 213 items

tests/test_auth.py .....                                                 [  2%]
tests/test_auth_adc.py ........                                          [  6%]
tests/test_automation.py ....                                            [  7%]
tests/test_cli.py ...............................                        [ 22%]
tests/test_cli_log.py ....                                               [ 24%]
tests/test_client.py ......                                              [ 27%]
tests/test_console.py ......                                             [ 30%]
tests/test_contents.py .....                                             [ 32%]
tests/test_exec.py ........                                              [ 36%]
tests/test_history.py ..                                                 [ 37%]
tests/test_ipynb_exec.py ...                                             [ 38%]
tests/test_keep_alive.py .................                               [ 46%]
tests/test_log_export.py .                                               [ 46%]
tests/test_pay.py .                                                      [ 47%]
tests/test_readme.py ....                                                [ 49%]
tests/test_repl.py ...............                                       [ 56%]
tests/test_resolution_logic.py .......                                   [ 59%]
tests/test_run.py ...............                                        [ 66%]
tests/test_runtime.py ........                                           [ 70%]
tests/test_state.py .......                                              [ 73%]
tests/test_streaming.py ..                                               [ 74%]
tests/test_update.py ................................                    [ 89%]
tests/test_url.py ............                                           [ 95%]
tests/test_utils.py ...                                                  [ 96%]
tests/test_version.py ...                                                [ 98%]
tests/test_whoami.py ....                                                [100%]
============================= 213 passed in 5.70s ==============================

[teeler]

Thanks - will merge after other checks run!