Fix GraalVM native image build error (#9593)

Motivation:

Error: Class that is marked for delaying initialization to run time got initialized during image building: io.netty.handler.codec.http2.Http2CodecUtil. Try marking this class for build-time initialization with --initialize-at-build-time=io.netty.handler.codec.http2.Http2CodecUtil
Error: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception
Error: Image build request failed with exit status 1
Modification:

After debugging, it seems the culprit is io.netty.handler.codec.http2.Http2ClientUpgradeCodec, which also needs runtime initialisation.

Result:

Fixes #micronaut-projects/micronaut-grpc#8

codec-http2/src/main/resources/META-INF/native-image/io.netty/codec-http2/native-image.properties

@@ -13,4 +13,4 @@
 # under the License.
 
 Args = --initialize-at-build-time=io.netty \
-       --initialize-at-run-time=io.netty.handler.codec.http2.Http2CodecUtil,io.netty.handler.codec.http2.DefaultHttp2FrameWriter
+       --initialize-at-run-time=io.netty.handler.codec.http2.Http2CodecUtil,io.netty.handler.codec.http2.Http2ClientUpgradeCodec,io.netty.handler.codec.http2.DefaultHttp2FrameWriter