tesla: remove empty Pre-AP firmware candidate

[daggerhashjack]

Remove the empty Tesla Pre-AP firmware table entry so exact firmware matching cannot select it vacuously. Preserve explicit Pre-AP selection and add regression coverage for normal firmware matching and Pre-AP interface parameters.

Verification:

• 90 safety tests passed, 8 skipped; the requested radar-gateway file does not exist in this branch
• 282 Tesla Pre-AP car tests passed
• firmware/interface suite: 762 passed, 143 skipped; four timing-baseline failures reproduced identically at parent cc1afdb (Tesla 0.30s vs stale 0.10s baseline; totals 7.70/8.30 vs 7.50/8.10)
• Ruff clean on touched files

[daggerhashjack]

SloPOS: this is ready for the independent CODEOWNER/last-push review. The change removes only the empty Pre-AP firmware entry and keeps explicit Pre-AP selection intact. All required checks are green; focused verification is in the PR body. Please approve if it looks good. Once this merges, I will update openpilot#14 to the merged gitlink and request a fresh review there.