Upgrade to Jetty 12.0.8

Closes gh-40250

spring-boot-project/spring-boot-dependencies/build.gradle

@@ -855,7 +855,7 @@ bom {
 			]
 		}
 	}
-	library("Jetty", "12.0.7") {
+	library("Jetty", "12.0.8") {
 		group("org.eclipse.jetty.ee10") {
 			imports = [
 				"jetty-ee10-bom"

spring-boot-project/spring-boot-starters/spring-boot-starter-jetty/build.gradle

@@ -12,9 +12,11 @@ dependencies {
 	api("org.eclipse.jetty.ee10:jetty-ee10-servlets")
 	api("org.eclipse.jetty.ee10:jetty-ee10-webapp")
 	api("org.eclipse.jetty.ee10.websocket:jetty-ee10-websocket-jakarta-server") {
+		exclude group: "jakarta.el",  module: "jakarta.el-api"
 		exclude group: "org.eclipse.jetty", module: "jetty-jndi"
 	}
 	api("org.eclipse.jetty.ee10.websocket:jetty-ee10-websocket-jetty-server") {
+		exclude group: "jakarta.el",  module: "jakarta.el-api"
 		exclude group: "org.eclipse.jetty", module: "jetty-jndi"
 	}
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/jetty/JettyServletWebServerFactory.java

@@ -684,6 +684,7 @@ public class JettyServletWebServerFactory extends AbstractServletWebServerFactor
 		}
 
 		@Override
+		@SuppressWarnings({ "deprecation", "removal" })
 		public ReadableByteChannel newReadableByteChannel() throws IOException {
 			return this.delegate.newReadableByteChannel();
 		}