Remove shared prepared statement cache (Refs #76)

tests/unit/host-observation-retention.test.ts

@@ -328,9 +328,9 @@ describe('routine host observation retention', () => {
         ).toEqual({ count: 2000 });
     });
 
-    it('reuses the same three delete statements across different batch sizes', async () => {
+    it('uses the same three delete query shapes across different batch sizes', async () => {
         const api = await setup();
-        const statements = new Map<string, ReturnType<typeof api.handle.prepare>>();
+        const deleteQueries = new Set<string>();
         for (const count of [1, 2, 7, 50, 500]) {
             api.handle.transaction(() => {
                 const insert = api.handle.prepare(`INSERT INTO ec_host_operations
@@ -346,13 +346,9 @@ describe('routine host observation retention', () => {
                 .filter((sql) => sql.startsWith('DELETE FROM ec_host_'));
             prepare.mockRestore();
             expect(deletes).toHaveLength(3);
-            for (const sql of deletes) {
-                const statement = api.handle.prepare(sql);
-                if (statements.has(sql)) expect(statement).toBe(statements.get(sql));
-                statements.set(sql, statement);
-            }
+            for (const sql of deletes) deleteQueries.add(sql);
         }
-        expect(statements.size).toBe(3);
+        expect(deleteQueries.size).toBe(3);
         expect(api.handle.pragma('foreign_key_check')).toEqual([]);
     });