Fix method not found error msg for server

Signed-off-by: JermaineHua <crazyhzm@apache.org>

Author: CrazyHZM

mcp/src/main/java/io/modelcontextprotocol/spec/McpClientSession.java

@@ -178,7 +178,7 @@ private Mono<McpSchema.JSONRPCResponse> handleIncomingRequest(McpSchema.JSONRPCR
 	record MethodNotFoundError(String method, String message, Object data) {
 	}
 
-	public static MethodNotFoundError getMethodNotFoundError(String method) {
+	private MethodNotFoundError getMethodNotFoundError(String method) {
 		switch (method) {
 			case McpSchema.METHOD_ROOTS_LIST:
 				return new MethodNotFoundError(method, "Roots not supported",

mcp/src/main/java/io/modelcontextprotocol/spec/McpServerSession.java

@@ -257,14 +257,8 @@ private Mono<Void> handleIncomingNotification(McpSchema.JSONRPCNotification noti
 	record MethodNotFoundError(String method, String message, Object data) {
 	}
 
-	static MethodNotFoundError getMethodNotFoundError(String method) {
-		switch (method) {
-			case McpSchema.METHOD_ROOTS_LIST:
-				return new MethodNotFoundError(method, "Roots not supported",
-						Map.of("reason", "Client does not have roots capability"));
-			default:
-				return new MethodNotFoundError(method, "Method not found: " + method, null);
-		}
+	private MethodNotFoundError getMethodNotFoundError(String method) {
+		return new MethodNotFoundError(method, "Method not found: " + method, null);
 	}
 
 	@Override