Remove Jetty NPN and ALPN support (#14049)

Motivation:
At this point, the JDK and OpenSSL both natively support ALPN, which
effectively means that ALPN is always available. NPN itself has been
obsolete for nearly 15 years, since the release of ALPN and its
subsequent widespread support. We no longer need Jetty to do ALPN or NPN
for us.

Modification:
Remove all code, build properties, and dependencies related to Jetty NPN
and ALPN.

Result:
This removes deprecated code and obsoleted features, and makes our
pom.xml files cleaner.

example/pom.xml

@@ -85,10 +85,6 @@
       <artifactId>${conscrypt.artifactId}</artifactId>
       <classifier>${conscrypt.classifier}</classifier>
     </dependency>
-    <dependency>
-      <groupId>org.eclipse.jetty.npn</groupId>
-      <artifactId>npn-api</artifactId>
-    </dependency>
     <dependency>
       <groupId>com.jcraft</groupId>
       <artifactId>jzlib</artifactId>

handler/pom.xml

@@ -90,16 +90,6 @@
       <artifactId>bctls-jdk18on</artifactId>
       <optional>true</optional>
     </dependency>
-    <dependency>
-      <groupId>org.eclipse.jetty.npn</groupId>
-      <artifactId>npn-api</artifactId>
-      <optional>true</optional>
-    </dependency>
-    <dependency>
-      <groupId>org.eclipse.jetty.alpn</groupId>
-      <artifactId>alpn-api</artifactId>
-      <optional>true</optional>
-    </dependency>
     <dependency>
       <groupId>${conscrypt.groupId}</groupId>
       <artifactId>${conscrypt.artifactId}</artifactId>

handler/src/main/java/io/netty5/handler/ssl/JdkAlpnApplicationProtocolNegotiator.java

@@ -28,7 +28,6 @@
 public final class JdkAlpnApplicationProtocolNegotiator extends JdkBaseApplicationProtocolNegotiator {
     private static final boolean AVAILABLE = Conscrypt.isAvailable() ||
                                              JdkAlpnSslUtils.supportsAlpn() ||
-                                             JettyAlpnSslEngine.isAvailable() ||
                                              BouncyCastle.isAvailable();
 
     private static final SslEngineWrapperFactory ALPN_WRAPPER = AVAILABLE ? new AlpnWrapper() : new FailureWrapper();
@@ -144,10 +143,6 @@ public SSLEngine wrapSslEngine(SSLEngine engine, BufferAllocator alloc,
             if (JdkAlpnSslUtils.supportsAlpn()) {
                 return new JdkAlpnSslEngine(engine, applicationNegotiator, isServer);
             }
-            if (JettyAlpnSslEngine.isAvailable()) {
-                return isServer ? JettyAlpnSslEngine.newServerEngine(engine, applicationNegotiator)
-                        : JettyAlpnSslEngine.newClientEngine(engine, applicationNegotiator);
-            }
             throw new UnsupportedOperationException("ALPN not supported. Unable to wrap SSLEngine of type '"
                     + engine.getClass().getName() + "')");
         }

handler/src/main/java/io/netty5/handler/ssl/JdkSslContext.java

@@ -414,31 +414,9 @@ static JdkApplicationProtocolNegotiator toNegotiator(ApplicationProtocolConfig c
                     .append(config.selectedListenerFailureBehavior()).append(" failure behavior").toString());
                 }
             }
-        case NPN:
-            if (isServer) {
-                switch(config.selectedListenerFailureBehavior()) {
-                case ACCEPT:
-                    return new JdkNpnApplicationProtocolNegotiator(false, config.supportedProtocols());
-                case FATAL_ALERT:
-                    return new JdkNpnApplicationProtocolNegotiator(true, config.supportedProtocols());
-                default:
-                    throw new UnsupportedOperationException(new StringBuilder("JDK provider does not support ")
-                    .append(config.selectedListenerFailureBehavior()).append(" failure behavior").toString());
-                }
-            } else {
-                switch(config.selectorFailureBehavior()) {
-                case FATAL_ALERT:
-                    return new JdkNpnApplicationProtocolNegotiator(true, config.supportedProtocols());
-                case NO_ADVERTISE:
-                    return new JdkNpnApplicationProtocolNegotiator(false, config.supportedProtocols());
-                default:
-                    throw new UnsupportedOperationException(new StringBuilder("JDK provider does not support ")
-                    .append(config.selectorFailureBehavior()).append(" failure behavior").toString());
-                }
-            }
         default:
             throw new UnsupportedOperationException(new StringBuilder("JDK provider does not support ")
-            .append(config.protocol()).append(" protocol").toString());
+                        .append(config.protocol()).append(" protocol").toString());
         }
     }