Add private APIs to get Python version before bootstrapping Python. ### Description

Add private APIs (module.\_py_version_{major,minor,micro}) to get the Python version before bootstrapping Python, and use it in Module.preRun to initialize filesystem.

### Checklists

- [x] Add / update tests

from pytest_pyodide import run_in_pyodide


@run_in_pyodide(packages=["sympy"])
def test_sympy(selenium):
    import sympy

    a, b = sympy.symbols("a,b")
    c = sympy.sqrt(a**2 + b**2)

    assert c.subs({a: 3, b: 4}) == 5

from pytest_pyodide import run_in_pyodide


@run_in_pyodide(packages=["sympy"])
def test_sympy(selenium):
    import sympy

    a, b = sympy.symbols("a,b")
    c = sympy.sqrt(a**2 + b**2)

    assert c.subs({a: 3, b: 4}) == 5
