feat: Allow associating created prompts with environments

[Luca Forstner (lforst)]

Depends on https://github.com/braintrustdata/braintrust/pull/11412

Allows to do

const project = braintrust.projects.create({ name: "my-project" });

project.prompts.create({
    // ...
    environments: ["test-env"],
});

[Abhijeet Prasad (AbhiPrasad)]

😎