`inngest init` with bad `--language` flag silently fails

[jpwilliams]

Describe the bug

Running inngest init with an incorrect --language flag (e.g. --language foo) will return successfully but not scaffold any steps.

To Reproduce Steps to reproduce the behavior:

1. inngest init --language foo
2. Answer any remaining questions
3. Observe that the created function has no files inside ./steps/step-1

Expected behavior

An error is thrown, or the CLI detects that the language doesn't exist and re-asks the question.

System info

• inngest-cli version: v0.5.10
• OS: MacOS