Update copyright headers to 2025 and clean up code

- Add copyright headers to files missing them
- Add blank lines after copyright headers for consistency
- Remove unused imports in test files
- Remove unnecessary keep-alive warning logs in WebFlux and WebMvc transport providers

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>

mcp-spring/mcp-spring-webmvc/src/main/java/io/modelcontextprotocol/server/transport/WebMvcStatelessServerTransport.java

@@ -1,3 +1,7 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ */
+
 package io.modelcontextprotocol.server.transport;
 
 import com.fasterxml.jackson.databind.ObjectMapper;

mcp-spring/mcp-spring-webmvc/src/main/java/io/modelcontextprotocol/server/transport/WebMvcStreamableServerTransportProvider.java

@@ -95,9 +95,6 @@ public class WebMvcStreamableServerTransportProvider implements McpStreamableSer
 
 	private McpTransportContextExtractor<ServerRequest> contextExtractor;
 
-	// private Function<ServerRequest, McpTransportContext> contextExtractor = req -> new
-	// DefaultMcpTransportContext();
-
 	/**
 	 * Flag indicating if the transport is shutting down.
 	 */
@@ -142,9 +139,6 @@ public class WebMvcStreamableServerTransportProvider implements McpStreamableSer
 
 			this.keepAliveScheduler.start();
 		}
-		else {
-			logger.warn("Keep-alive interval is not set or invalid. No keep-alive will be scheduled.");
-		}
 	}
 
 	@Override