Add sys.stdlib_module_names for Python 3.10

[lancelote]

sys.stdlib_module_names was introduced in Python 3.10

• bpo-42955: Add sys.stdlib_module_names: list of stdlib module names (Python and extension modules)
• PR1 bpo-42955: Add sys.modules_names cpython#24238: Add sys.modules_names
• PR2 bpo-42955: Rename module_names to sys.stdlib_module_names cpython#24332: Rename module_names to sys.stdlib_module_names

[srittau]

Thanks!

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉