omitir warnings de 'availability' y 'wasm-notavail'

[cmaureir]

edit: including explanation

the whole story on the 'availability' warnings are that there is a .. availability:: command in the cpython docs that include, in some cases, stuff from the 'wasm-availability' file. So we have references "within" the 'availabiliy' command.

as you can see, the entry has no mention of WASM or wahtsover in some entries, like "Unix, Windows",
but still will generate the following warning:

cpython/Doc/library/os.rst:: WARNING: inconsistent term references in translated message. original: [':ref:`Availability <availability>`', ':ref:`wasm-availability`'], translated: [':ref:`Disponibilidad <availability>`']

The reason that due to the internal reference to 'wasm-availability' , even in cases like this entry, where it's only Unix and Windows, for example:

https://docs.python.org/3.11/library/os.html?highlight=os#os.getenv

it generates the reference to the 'Availability' page, which inside has the 'wasm-availability' inside:

https://docs.python.org/3.11/library/intro.html#availability

Additionally, the wasm-notavail file is excluded to avoid the warning related to the file not being inclued in any index. We could have add :orphan: to the file inside cpython but we do it via the exclude patterns to avoid touching files on the submodule.

[cmaureir]

Gracias por el review @raulcd 💯

[cmaureir]

Mencionando #1845 para que esté enlazado ese issue con este pr