RSky-Jetstream-Subscriber: Code Cleanup

[TheRipperoni]

Summary

Ran Clippy on Jetstream and removed unused imports. It was merged in before the latest pipeline updates so it skipped some checks that have now been properly implemented. No new features or changes otherwise

Related Issues

N/A

Changes

• Feature implementation
• Bug fix
• Documentation update
• Other (please specify): Technical Debt cleanup

Checklist

• I have tested the changes (including writing unit tests).
• I confirm that my implementation aligns with the canonical Typescript implementation and/or atproto spec
• I have updated relevant documentation.
• I have formatted my code correctly
• I have provided examples for how this code works or will be used

[rudyfraser]

Thanks for doing this.