Fix pulsar example compile error (#7077)

example/pulsar/pom.xml

@@ -34,7 +34,14 @@
         <dependency>
             <groupId>org.apache.pulsar</groupId>
             <artifactId>pulsar-client</artifactId>
-            <version>2.6.0</version>
+            <version>2.6.4</version>
+            <!-- exclude guava for avoiding compile error, guava can be found in other module -->
+            <exclusions>
+                <exclusion>
+                    <groupId>com.google.guava</groupId>
+                    <artifactId>guava</artifactId>
+                </exclusion>
+            </exclusions>
         </dependency>
         <dependency>
             <groupId>org.apache.iotdb</groupId>