HBASE-28286 Remove rename-pdf step in root pom on branch-3 (#5596)

Signed-off-by: Nihal Jain <nihaljain@apache.org>

pom.xml

@@ -2722,27 +2722,6 @@
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-antrun-plugin</artifactId>
-        <version>${maven.antrun.version}</version>
-        <inherited>false</inherited>
-        <!-- Rename the book.pdf generated by asciidoctor -->
-        <executions>
-          <execution>
-            <id>rename-pdf</id>
-            <goals>
-              <goal>run</goal>
-            </goals>
-            <phase>site</phase>
-            <configuration>
-              <target name="rename file">
-                <move file="${project.reporting.outputDirectory}/book.pdf" tofile="${project.reporting.outputDirectory}/apache_hbase_reference_guide.pdf"/>
-              </target>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>buildnumber-maven-plugin</artifactId>