C2A: Conan deprecates CONAN_USERNAME and CONAN_CHANNEL

Description of Problem, Request, or Question

After deprecating environament variables CONAN_USERNAME and CONAN_CHANNEL, I think that we should get rid of them in this repo too, it shouldn’t be a reliable way to feed user/channel to packages built with cpt.

Link to deprecation notice in the docs: https://docs.conan.io/en/latest/reference/env_vars.html#conan-username-conan-channel

If we agree to remove these variables here, it would be nice to remove them from the conan new --ci-* generated files too.

[uilianries]

I’m not sure. I see many users running CPT on their companies, which doesn’t reflect what we are doing on Conan Center Index. Probably we will break many users/companies dropping it. I vote for supporting both cases on CPT.

[jgsogo]

conan-package-tools can still get those variables from the environment and pass them to Conan, that won’t make a difference, and we will check that everything keeps working the same. For Conan 2.0 we will thing about removing other environment variables too (https://github.com/conan-io/conan/issues/5270).

Probably this all is a result of my poor explanation when I opened this issue: Conan is deprecating those variables, so conan-package-tools should read the environment and pass them explicitly to conan create or to the conan_api (I don’t know the internals of this repo).