Enforce src-tauri Cargo.lock gitignore

[Gearhartlove]

Is your feature request related to a problem? Please describe.
Yes, our Cargo.lock is committing when it should not be, which clutters commits and can cause annoying merges.

Describe the solution you'd like
git rm --cached Cargo.lock from src-tauri project

Describe alternatives you've considered
NA
Additional context
N/A

Acceptance Criteria

• src-tauri/Cargo.lock is gone.