chore: gif cleanup for pytests

[abanuelo]

Description

After the simulation.gif has been generated by running the test_newtonian.py file, we should delete this file. Also we should ignore simulation.gif for git version control!

Issue Link

Checklist

• [X] I have tested the changes locally via pytest and/or other means
• [ ] I have added or updated relevant documentation
• [ ] I have autoformatted the code with black and isort
• [ ] I have added test cases (if applicable)

Additional Notes

[codecov[bot]]

Codecov Report

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

Project coverage is 91.30%. Comparing base (d7679fb) to head (1d14751).

Additional details and impacted files

[](https://app.codecov.io/gh/BerkeleyLearnVerify/Scenic/pull/285?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BerkeleyLearnVerify) ```diff @@ Coverage Diff @@ ## main #285 +/- ## ========================================== - Coverage 91.32% 91.30% -0.02% ========================================== Files 54 54 Lines 13515 13520 +5 ========================================== + Hits 12343 12345 +2 - Misses 1172 1175 +3 ``` [see 4 files with indirect coverage changes](https://app.codecov.io/gh/BerkeleyLearnVerify/Scenic/pull/285/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BerkeleyLearnVerify)