Remove explicit SLF4J binding from city-time-weather ADK tutorial.

The `slf4j-simple` dependency and the exclusion of `logback-classic` are removed, allowing the default logging implementation provided by `google-adk-dev` to be used.

PiperOrigin-RevId: 888114465

Author: vorburger

tutorials/city-time-weather/pom.xml

@@ -36,16 +36,6 @@
       <groupId>com.google.adk</groupId>
       <artifactId>google-adk-dev</artifactId>
       <version>${project.version}</version>
-      <exclusions>
-        <exclusion>
-          <groupId>ch.qos.logback</groupId>
-          <artifactId>logback-classic</artifactId>
-        </exclusion>
-      </exclusions>
-    </dependency>
-    <dependency>
-      <groupId>org.slf4j</groupId>
-      <artifactId>slf4j-simple</artifactId>
     </dependency>
   </dependencies>
 </project>