fix: Upgrade diff to fix DoS vulnerabilities (#11621)
## Summary
- Upgrades `diff` from 5.1.0 to 5.2.2 in `@turbo/codemod` (fixes
TURBO-5178)
- Updates lockfile to resolve `diff@4.0.4` for ts-node's transitive
dependency (fixes TURBO-5177)
Both versions patch a Regular Expression Denial of Service (ReDoS)
vulnerability.
## Testing
- `@turbo/codemod`: 217 tests passing
- `@turbo/gen`: 9 tests passing
- Both packages build successfully
