Enable Hydra composition for the `dvc repro` command

[tapyu]

Hi!

I am trying to use dvc along with Hydra. For some reason, params.yaml is composed only when I run dvc exp run. When I run dvc repro, nothing happens. Why? I think it would be a great ideal to also compose params.yaml for dvc repro.

[skshetry]

@tapyu, could you please share why you don't use dvc exp run?

[tapyu]

dvc exp run is for experimentation, parameter tuning, and exploratory modeling, while dvc repro is for production, stable pipelines, and CI/CD.

Different purposes, different commands. Fair enough. However, I don't find it fair enough not composing Hydra configuration file when dvc repro is run.