add cleanup delay to driver

[drmorr0]

• [x] I certify that this PR does not contain any code that has been generated with GitHub Copilot or any other AI-based code generation tool, in accordance with this project's policies.

Description

Waits until the driver has fully cleaned up the old simulation before starting a new one

Testing done

• make test -- new tests covering the cleanup function in the driver
• manual testing

Additional info

Resolves #113

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 95.45455% with 1 line in your changes missing coverage. Please review.

Project coverage is 73.03%. Comparing base (e5a5c5d) to head (2bad960).

:exclamation: Current head 2bad960 differs from pull request most recent head e4f86ea

Please upload reports for the commit e4f86ea to get more accurate results.

Files	Patch %	Lines
driver/runner.rs	95.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #115 +/- ## ========================================== + Coverage 72.80% 73.03% +0.23% ========================================== Files 39 39 Lines 2118 2140 +22 ========================================== + Hits 1542 1563 +21 - Misses 576 577 +1 ```

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