📝 Add docstring check to ruff and fix respective errors

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 93.1%. Comparing base (b1a7118) to head (e5b8d65).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #331 +/- ## ======================================= + Coverage 92.9% 93.1% +0.2% ======================================= Files 47 47 Lines 2437 2437 ======================================= + Hits 2264 2270 +6 + Misses 173 167 -6 ``` | [Flag](https://app.codecov.io/gh/cda-tum/mqt-bench/pull/331/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cda-tum) | Coverage Δ | | |---|---|---| | [python](https://app.codecov.io/gh/cda-tum/mqt-bench/pull/331/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cda-tum) | `93.1% <100.0%> (+0.2%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cda-tum#carryforward-flags-in-the-pull-request-comment) to find out more.

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