Handle 204 No Content status in response processing

Fixes #1303

Author: hdu-sdlzx

src/client/streamableHttp.ts

@@ -555,8 +555,8 @@ export class StreamableHTTPClientTransport implements Transport {
             this._hasCompletedAuthFlow = false;
             this._lastUpscopingHeader = undefined;
 
-            // If the response is 202 Accepted, there's no body to process
-            if (response.status === 202) {
+            // If the response is 202 Accepted or 204 No Content, there's no body to process
+            if (response.status === 202 || response.status === 204) {
                 await response.body?.cancel();
                 // if the accepted notification is initialized, we start the SSE stream
                 // if it's supported by the server