Add Python 3.14 support

Update the Python requirement in pyproject.toml and the version matrix in .github/workflows/tests-unit.yaml. Start by reviewing those entries and the existing unit-test workflow, then run the unit tests on Python 3.14. Done means Python 3.14 is declared supported and CI verifies it alongside the existing versions.

Summary

Python 3.14 is released. tinyagent currently caps supported versions at <3.14 in pyproject.toml and does not test against 3.14 in CI.

This issue tracks the work needed to declare and verify Python 3.14 support.

Proposed changes

1. pyproject.toml — raise the upper bound:

   requires-python = ">=3.11,<3.15"
   

2. .github/workflows/tests-unit.yaml — add 3.14 to the unit test matrix:

   python-version: ['3.11', '3.12', '3.13', '3.14']
   

Compatibility notes

A quick audit of the codebase found no use of APIs removed in Python 3.14 (e.g. pkgutil.find_loader, typing.Hashable/Sized, sys.last_*).

Existing unit tests pass on Python 3.14 locally with no source changes required.

Optional follow-ups (not blocking)

• Bump language_version in .pre-commit-config.yaml (nbstripout hook) from python3.13 to python3.14
• Replace deprecated asyncio.iscoroutinefunction() with inspect.iscoroutinefunction() (deprecated in 3.14, removal planned for 3.16) in:
  • src/tinyagent/agent.py
  • src/tinyagent/callbacks/wrapper.py
  • src/tinyagent/tools/wrappers.py

README and CONTRIBUTING already say "Python 3.11+" and do not need updates.