Remove additional generation of dependencies when building CI images

[potiuk]

When generated dependencies are not properly updated, we had a special step where the dependencies were generated "just in case" before CI image was built, because otherwise building the CI image could have failed with strange "failed because of conflicting dependencies" without a clue what was the root cause.

However, the pre-commit did not return error exit code - because for the pre-commit, it is enough that a file is modified during pre-commit to fail the pre-commit in general.

That had a nasty side effect because the built CI image actually already contained properly generated dependencies (by this step), and it did not properly detected cases where the ones in the repository were added manually and not generated with pre-commit.

This PR fixes it - instead of generating and building such image in CI it will now fail the CI image building step but with clear instructions what to do.

The CI job step uses now regular breeze command rather than running the script manually but also the script returns error code in case the generated dependencies have been updated.

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[potiuk]

actually I need to close that one. I need to run it from the "airflow" repo to test it properly.