Improve `module.rst` C-API docs

[sobolevn]

There are multiple places in https://github.com/python/cpython/blob/main/Doc/c-api/module.rst where exception are not mentioned in the docs.

Like:

cpython/Doc/c-api/module.rst

Line 685 in 690b935

Return 0 on success or -1 on failure.

Some functions do not even declare that they can return NULL. Like:

cpython/Doc/c-api/module.rst

Lines 457 to 470 in 690b935

	.. c:function:: PyObject * PyModule_FromDefAndSpec2(PyModuleDef *def, PyObject *spec, int module_api_version)
	Create a new module object, given the definition in *def* and the
	ModuleSpec *spec*, assuming the API version *module_api_version*.
	If that version does not match the version of the running interpreter,
	a :exc:`RuntimeWarning` is emitted.
	.. note::
	Most uses of this function should be using :c:func:`PyModule_FromDefAndSpec`
	instead; only use this if you are sure you need it.
	.. versionadded:: 3.5

I will send a PR with the fix.

Linked PRs

• gh-121615: Improve module.rst C-API docs with better error descriptions #121616
• [3.13] gh-121615: Improve module.rst C-API docs with better error descriptions (GH-121616) #121618
• [3.12] gh-121615: Improve module.rst C-API docs with better error descriptions (GH-121616) #121619