[Urgent] Update Transifex Calls to APIv3

[Daltz333]

See notice at the top of https://docs.transifex.com/api/introduction

This tool will no longer be functional as of April 7th.

[Daltz333]

Whoops, I incorrectly assumed this tool made calls to the transifex api. After digging through the source, this does not seem to be the case.

[shimizukawa]

Thanks for your reporting!

As you are aware, sphinx-intl does not call transifex-api. However, it uses transifex-client, which is deprecated in accordance with the API.

sphinx-intl/setup.py

Lines 14 to 17 in 6edc8aa

	extras_require = {
	'transifex': [
	'transifex_client>=0.11'
	],

https://docs.transifex.com/client/introduction

Therefore, we need to switch to calling the new transifex cli by the end of 2022.

[rffontenelle]

@shimizukawa Actually, sphinx_intl/transifex.py seems to import txclib.utils, so it also relies on a Python library (the one that will sunset soon) that will not be available in the new golang implementation of the CLI tool.