Fix CI: add sqlite-jdbc test dep and remove MockLlmProvider suite

- Add sqlite-jdbc test dependency to data-agent-engine pom.xml
- Remove DataAgentMockLlmSuite which depends on MockLlmProvider from a later PR

Author: wangzhigang1999

externals/kyuubi-data-agent-engine/pom.xml

@@ -59,6 +59,12 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>org.xerial</groupId>
+            <artifactId>sqlite-jdbc</artifactId>
+            <scope>test</scope>
+        </dependency>
+
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>