is_abi3 preprocessing selector will become a boolean

[isuruf]

With https://github.com/conda-forge/conda-smithy/commit/afbc8d1637001c46f39b8bd76d3fab19e091ea64

Things like https://github.com/conda-forge/polars-feedstock/blob/main/recipe/recipe.yaml#L27 will need to be fixed

[beckermr]

Is there a way to add a lint to smithy for this?

I am guessing we're going to miss it or forget if we do not.

[beckermr]

here are all of the feedstocks: https://github.com/search?q=org%3Aconda-forge%20is_abi3%20%3D%3D%20%27true%27&type=code

[beckermr]

We've added a lint for this so we should be good to go in terms of warnings for folks who need to migrate.

[beckermr]

This will land in smithy 3.48.0