Merge pyodide_py into python_stdlib.zip. ### Description

Merges pyodide_py.tar into python_stdlib.zip. This reduces the number of network requests during the initialization.

The original intention of splitting pyodide_py.tar from pyodide.asm.data was to give users an option to provide custom files (#2023), which is now available by modifying python_stdlib.zip directly. So I think there is no reason to have both python_stdlib.zip and pyodide_py.tar.

### Checklists

- [x] Add a [CHANGELOG](https://github.com/pyodide/pyodide/blob/main/docs/project/changelog.md) entry
- [x] Add / update tests

import pytest
from pytest_pyodide import run_in_pyodide


@pytest.mark.parametrize(
    "pattern,name,flags,expected",
    [
        ("foo", "bar", 0, False),
        ("f*", "foo", 0, True),
        ("f*bar", "f/bar", 0, True),
        ("f*bar", "f/bar", "fnmatch.FNM_PATHNAME", False),
    ],
)
def test_fnmatch(selenium_module_scope, pattern, name, flags, expected):
    selenium = selenium_module_scope
    selenium.load_package("cffi_example")
    result = selenium.run(
        f"""
        from cffi_example import fnmatch
        fnmatch.fnmatch({pattern!r}, {name!r}, {flags})
        """
    )
    assert result == expected


@run_in_pyodide(
    packages=["cffi_example"],
)
def test_person(selenium_module_scope):
    from cffi_example.person import Person

    p = Person("Alex", "Smith", 72)
    assert p.get_age() == 72
    assert p.get_full_name() == "Alex Smith"

    p = Person("x" * 100, "y" * 100, 72)
    assert p.get_full_name() == "x" * 100

import pytest
from pytest_pyodide import run_in_pyodide


@pytest.mark.parametrize(
    "pattern,name,flags,expected",
    [
        ("foo", "bar", 0, False),
        ("f*", "foo", 0, True),
        ("f*bar", "f/bar", 0, True),
        ("f*bar", "f/bar", "fnmatch.FNM_PATHNAME", False),
    ],
)
def test_fnmatch(selenium_module_scope, pattern, name, flags, expected):
    selenium = selenium_module_scope
    selenium.load_package("cffi_example")
    result = selenium.run(
        f"""
        from cffi_example import fnmatch
        fnmatch.fnmatch({pattern!r}, {name!r}, {flags})
        """
    )
    assert result == expected


@run_in_pyodide(
    packages=["cffi_example"],
)
def test_person(selenium_module_scope):
    from cffi_example.person import Person

    p = Person("Alex", "Smith", 72)
    assert p.get_age() == 72
    assert p.get_full_name() == "Alex Smith"

    p = Person("x" * 100, "y" * 100, 72)
    assert p.get_full_name() == "x" * 100
