Remove obsolete role attributes for tab groups in the reference manual

Since we now use asciidoctor-tabs instead of spring-asciidoctor-backends,
we no longer need the `role="primary"` and `role="secondary"` attributes
for tab groups.

Closes gh-33506

framework-docs/modules/ROOT/pages/web/webmvc-view/mvc-script.adoc

@@ -57,7 +57,7 @@ The following example uses Mustache templates and the Nashorn JavaScript engine:
 ======
 Java::
 +
-[source,java,indent=0,subs="verbatim,quotes",role="primary"]
+[source,java,indent=0,subs="verbatim,quotes"]
 ----
 	@Configuration
 	@EnableWebMvc
@@ -82,7 +82,7 @@ Java::
 
 Kotlin::
 +
-[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
+[source,kotlin,indent=0,subs="verbatim,quotes"]
 ----
 	@Configuration
 	@EnableWebMvc
@@ -124,7 +124,7 @@ The controller would look no different for the Java and XML configurations, as t
 ======
 Java::
 +
-[source,java,indent=0,subs="verbatim,quotes",role="primary"]
+[source,java,indent=0,subs="verbatim,quotes"]
 ----
 	@Controller
 	public class SampleController {
@@ -140,7 +140,7 @@ Java::
 
 Kotlin::
 +
-[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
+[source,kotlin,indent=0,subs="verbatim,quotes"]
 ----
 	@Controller
 	class SampleController {
@@ -192,7 +192,7 @@ The following example shows how to do so:
 ======
 Java::
 +
-[source,java,indent=0,subs="verbatim,quotes",role="primary"]
+[source,java,indent=0,subs="verbatim,quotes"]
 ----
 	@Configuration
 	@EnableWebMvc
@@ -217,7 +217,7 @@ Java::
 
 Kotlin::
 +
-[source,kotlin,indent=0,subs="verbatim,quotes",role="secondary"]
+[source,kotlin,indent=0,subs="verbatim,quotes"]
 ----
 	@Configuration
 	@EnableWebMvc