Remove last black run from lint script

Many (all?) packages in this project run black twice (one time at the end of the lint process [e.g.](https://github.com/democritus-project/d8s-algorithms/blob/3ef59b58c0f3478325b4f0a2455c07a6873f0237/docker/lint.sh#L19)). We should remove this last run of black.

Start by inspecting docker/lint.sh in the linked example repository and compare lint scripts across the project packages. Identify the final Black invocation that duplicates an earlier run, remove the redundant invocation from each affected script, and verify that the lint process still completes with the intended single Black run.

Written by the indexing model from the issue text.