fix(ci): resolve netty-tcnative UnsatisfiedLinkError (Round 8)

Http2ProtocolProxyHandler hard-coded SslProvider.OPENSSL which requires
netty-tcnative-boringssl-static native library. That dependency was
removed in Round 4 to fix a Bazel cycle dependency.

Apply the same fallback pattern used by MultiProtocolTlsHelper and
ProxyAndTlsProtocolNegotiator: check OpenSsl.isAvailable() and fall
back to SslProvider.JDK when the native library is not present.

Author: qianye1001

proxy/src/main/java/org/apache/rocketmq/proxy/remoting/protocol/http2proxy/Http2ProtocolProxyHandler.java

@@ -27,6 +27,7 @@
 import io.netty.handler.codec.haproxy.HAProxyMessageEncoder;
 import io.netty.handler.ssl.ApplicationProtocolConfig;
 import io.netty.handler.ssl.ApplicationProtocolNames;
+import io.netty.handler.ssl.OpenSsl;
 import io.netty.handler.ssl.SslContext;
 import io.netty.handler.ssl.SslContextBuilder;
 import io.netty.handler.ssl.SslHandler;
@@ -63,9 +64,10 @@ public Http2ProtocolProxyHandler() {
             if (TlsMode.DISABLED.equals(tlsMode)) {
                 sslContext = null;
             } else {
+                SslProvider provider = OpenSsl.isAvailable() ? SslProvider.OPENSSL : SslProvider.JDK;
                 sslContext = SslContextBuilder
                     .forClient()
-                    .sslProvider(SslProvider.OPENSSL)
+                    .sslProvider(provider)
                     .trustManager(InsecureTrustManagerFactory.INSTANCE)
                     .applicationProtocolConfig(new ApplicationProtocolConfig(
                         ApplicationProtocolConfig.Protocol.ALPN,