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/mvc.xml

@@ -749,9 +749,9 @@ public class HelloWorldController {
     xmlns:context="http://www.springframework.org/schema/context"
     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
         http://www.springframework.org/schema/context
-        http://www.springframework.org/schema/context/spring-context-3.0.xsd">
+        http://www.springframework.org/schema/context/spring-context.xsd">
 
     <context:component-scan base-package="org.springframework.samples.petclinic.web"/>
 
@@ -4315,7 +4315,7 @@ public class ErrorController {
     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">
 
     <lineannotation>&lt;!-- this bean with the well known name generates view names for us --&gt;</lineannotation>
     &lt;bean id="viewNameTranslator"
@@ -4567,9 +4567,9 @@ public class WebConfig {
     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-3.1.xsd
+        http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/mvc
-        http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd"&gt;
+        http://www.springframework.org/schema/mvc/spring-mvc.xsd"&gt;
 
     &lt;mvc:annotation-driven /&gt;
 
@@ -4713,7 +4713,7 @@ public class WebConfig extends WebMvcConfigurerAdapter {
         <para>To customize the default configuration of
         <literal>&lt;mvc:annotation-driven /&gt;</literal> check what
         attributes and sub-elements it supports. You can view the
-        <link xl:href="http://static.springsource.org/schema/mvc/spring-mvc-3.1.xsd">Spring MVC XML schema</link>
+        <link xl:href="http://static.springsource.org/schema/mvc/spring-mvc.xsd">Spring MVC XML schema</link>
         or use the code completion feature of your IDE to discover
         what attributes and sub-elements are available.
         The sample below shows a subset of what is available:</para>