Remove Safety as a dependency

[bachya]

Describe what the PR does:

We aren't actively using Safety, and we have to pay for it to use it in CI/CD. GitHub CodeQL effectively does the same thing.

Does this fix a specific issue?

N/A

Checklist:

• [ ] Confirm that one or more new tests are written for the new functionality.
• [x] Run tests and ensure everything passes (with 100% test coverage).
• [ ] Update README.md with any new documentation.

[codeclimate[bot]]

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