Python 3.14

[bobmyhill]

This pull request updates the minimum required Python version for the project to 3.10 and adds support for Python 3.14.

This version should be merged when numba 0.63 is released (https://github.com/numba/numba/releases, numba/numba#9957)

The changes are listed below.

• Changed project requirements and documentation (Readme.md, burnman/__init__.py, pyproject.toml) to require Python 3.10 or newer.
• Updated pyproject.toml to specify compatible numba versions for Python 3.14 and above.
• Removed a custom implementation of cached_property in burnman/classes/material.py and switched to using the standard library's functools.cached_property, now available due to the raised minimum Python version.
• Updated workflow files