test(plugin-security): drop the ③.11 pin's unused agent predicate

Claude-Session: https://claude.ai/code/session_01FatVyDAFEST48jZDQcbheU
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/plugins/plugin-security/src/objects/default-row-scope-declarations.test.ts

@@ -431,7 +431,6 @@ describe('a deployment with the shipped baseline is byte-for-byte unchanged on t
   // the one source every door and every explain composes from, for all four.
   const EXPLAINED = ['read'] as const;
   const COLLECTED = ['select', 'insert', 'update', 'delete'] as const;
-  const isAgent = (persona: string) => BASELINE_PERSONAS[persona].principalKind === 'agent';
 
   it('every persona reads every declarer exactly as without the declarations, and is explained the same', { timeout: 30_000 }, async () => {
     const after = await bootBaseline(true);