Apply request-handler-ref to CsrfAuthenticationStrategy

Closes gh-16801

Author: sjohnr

config/src/test/java/org/springframework/security/config/http/CsrfConfigTests.java

@@ -22,7 +22,6 @@
 import jakarta.servlet.Filter;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
-
 import org.eclipse.jetty.http.HttpStatus;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;