check that python version is valid

[KenniVelez]

https://github.com/replicate/cog/blob/27c63bf24d8f99cb78ad1c9da74d457410327295/pkg/dockerfile/generator.go#L1-L270

[zeke]

Hi @KenniVelez. Thanks for reporting. Can you add a bit more detail to clarify the issue you're experiencing?

[anish-sahoo]

Closing as python_version validation is now enforced during config loading, rejecting malformed or unsupported versions before Dockerfile generation.