Remove xsd versions from reference samples

Remove all xsd versions from the reference manual samples in favor of
"versionless" XSDs. For example, spring-beans-3.0.xsd becomes
spring-beans.xsd

Issue: SPR-10010

src/reference/docbook/remoting.xml

@@ -1042,7 +1042,7 @@ public class SimpleCheckingAccountService implements CheckingAccountService {
 <beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
-        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
+        http://www.springframework.org/schema/beans/spring-beans.xsd">
 
     <bean id="connectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
         <property name="brokerURL" value="tcp://ep-t43:61616"/>
@@ -1064,7 +1064,7 @@ public class SimpleCheckingAccountService implements CheckingAccountService {
 <beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
-         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
+         http://www.springframework.org/schema/beans/spring-beans.xsd">
 
     <bean id="checkingAccountService"
           class="org.springframework.jms.remoting.JmsInvokerServiceExporter">
@@ -1109,7 +1109,7 @@ public class Server {
 <beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
-        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
+        http://www.springframework.org/schema/beans/spring-beans.xsd">
 
     <bean id="checkingAccountService"
           class="org.springframework.jms.remoting.JmsInvokerProxyFactoryBean">