Add sanity check for poetry files

Context

Wait for opam-repository!119 (merged) and rebase. Check opam-repository and tezos/tezos match about poetry.lock and pyproject.toml. I am not fully happy on the solution... But does the job.

Manually testing the MR

Modify poetry.lock or pyproject.toml, run

 gitlab-runner exec docker sanity

Checklist

• Provide automatic testing (see the testing guide).

Reviewers

@pirbo