Don't raise conflicting basepython warnings when -e option has been used to target a different environment

[prashantmital]

First-time contributor alert!

Closes #1124

This only runs the basepython conflict check if the current environment is amongst the ones requested to be targeted by the user via the -e option.

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[asottile]

seems fine, mind adding a quick test and a changelog entry? can probably copy the other basepython conflict test, expand it to have a second testenv that doesn't have a conflict and assert the output there

I think this'll also be magicallyfixed by the rewrite that @gaborbernat is working on (via lazily-evaluated environment configurations)

[gaborbernat]

Add a changelog entry and it's okay. Granted tox 4 will fix this, but that's probably few months down the line for now due to its overall complexity and lack to time on my side, so no need to hold progress until then.

[gaborbernat]

Ideally we would want a test too, for validation.

[prashantmital]

I'll work on the test and update the ticket in a few days.

[gaborbernat]

@prashantmital still interested in pushing this over the line?

[prashantmital]

Sorry @gaborbernat I just don't have the bandwidth to finish this up. Its also not a high-priority issue since the error message is purely cosmetic and will be resolved by the rewrite that was mentioned at some point in this thread.

Thanks for your work in maintaining this project. Cheers!