Add missing dependency and remove warnings

See gh-22171

framework-docs/framework-docs.gradle

@@ -78,6 +78,7 @@ dependencies {
 	api("jakarta.validation:jakarta.validation-api")
 	api("org.aspectj:aspectjweaver")
 	api("io.projectreactor.netty:reactor-netty-http")
+	api("org.eclipse.jetty.websocket:jetty-websocket-jetty-api")
 
 	implementation(project(":spring-core-test"))
 	implementation("org.assertj:assertj-core")