Reassess Numba support for recent Python versions and Update test coverage

[XingerTang]

See #36 (comment)

The Numba package provides support for recent Python versions, but only with the most recent releases.
However, for the most recent releases, Numba also drops support for Python versions less than 3.10: https://github.com/numba/numba/blob/9424eeeecbce5de2e2763ea338a43ccc658606fb/setup.py#L22

Our current dependency requirement for Numba is numba>=0.49.0, which requires Python version >=3.6.

To ensure the dependency won't lead to issues, we can do the following:

• Change the requires-python in the pyproject.toml to >= 3.6, < 3.14.
• Extend the tests in the tests.yml workflow to not only test the 3.11.x version Python.
• Check recent Numba releases regularly.

[gregorgorjanc]

Looks like a reasonable plan @XingerTang !