needs to remove some abstract keyword from WebSocket SPEC API

We need to remove the abstract keyword from some WebSocket API methods to address signature test failures:

javatest.batch] Missing Methods
[javatest.batch] ---------------
[javatest.batch]
[javatest.batch] jakarta.websocket.Decoder: method public void jakarta.websocket.Decoder.destroy()
[javatest.batch] — affected jakarta.websocket.Decoder$TextStream,jakarta.websocket.Decoder$Text,jakarta.websocket.Decoder$BinaryStream,jakarta.websocket.Decoder$Binary
[javatest.batch] jakarta.websocket.Decoder: method public void jakarta.websocket.Decoder.init(jakarta.websocket.EndpointConfig)
[javatest.batch] — affected jakarta.websocket.Decoder$TextStream,jakarta.websocket.Decoder$Text,jakarta.websocket.Decoder$BinaryStream,jakarta.websocket.Decoder$Binary
[javatest.batch] jakarta.websocket.Encoder: method public void jakarta.websocket.Encoder.destroy()
[javatest.batch] — affected jakarta.websocket.Encoder$TextStream,jakarta.websocket.Encoder$Text,jakarta.websocket.Encoder$BinaryStream,jakarta.websocket.Encoder$Binary
[javatest.batch] jakarta.websocket.Encoder: method public void jakarta.websocket.Encoder.init(jakarta.websocket.EndpointConfig)
[javatest.batch] — affected jakarta.websocket.Encoder$TextStream,jakarta.websocket.Encoder$Text,jakarta.websocket.Encoder$BinaryStream,jakarta.websocket.Encoder$Binary
[javatest.batch]
[javatest.batch] Added Methods
[javatest.batch] -------------
[javatest.batch]
[javatest.batch] jakarta.websocket.Decoder: method public abstract void jakarta.websocket.Decoder.destroy()
[javatest.batch] — affected jakarta.websocket.Decoder$TextStream,jakarta.websocket.Decoder$Text,jakarta.websocket.Decoder$BinaryStream,jakarta.websocket.Decoder$Binary
[javatest.batch] jakarta.websocket.Decoder: method public abstract void jakarta.websocket.Decoder.init(jakarta.websocket.EndpointConfig)
[javatest.batch] — affected jakarta.websocket.Decoder$TextStream,jakarta.websocket.Decoder$Text,jakarta.websocket.Decoder$BinaryStream,jakarta.websocket.Decoder$Binary
[javatest.batch] jakarta.websocket.Encoder: method public abstract void jakarta.websocket.Encoder.destroy()
[javatest.batch] — affected jakarta.websocket.Encoder$TextStream,jakarta.websocket.Encoder$Text,jakarta.websocket.Encoder$BinaryStream,jakarta.websocket.Encoder$Binary
[javatest.batch] jakarta.websocket.Encoder: method public abstract void jakarta.websocket.Encoder.init(jakarta.websocket.EndpointConfig)
[javatest.batch] — affected jakarta.websocket.Encoder$TextStream,jakarta.websocket.Encoder$Text,jakarta.websocket.Encoder$BinaryStream,jakarta.websocket.Encoder$Binary
[javatest.batch]