SEC-3063: rm ConditionalOnMissingBean for @Primary

ConditionalOnMissingBean can only work in a Spring Boot environment. This
means this approach is flawed.

Instead users that wish to override requestDataValueProcessor can use
@Primary.

config/src/test/java/org/springframework/security/config/annotation/web/configurers/CsrfConfigurerNoWebMvcTests.java

@@ -24,6 +24,7 @@ import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
@@ -78,6 +79,7 @@ public class CsrfConfigurerNoWebMvcTests {
 	@EnableWebSecurity
 	static class EnableWebOverrideRequestDataConfig {
 		@Bean
+		@Primary
 		public RequestDataValueProcessor requestDataValueProcessor() {
 			return mock(RequestDataValueProcessor.class);
 		}