fix: Add JsonInclude annotation to notification records for proper serialization (#552)

Add @JsonInclude(JsonInclude.Include.NON_ABSENT) to ResourcesUpdatedNotification
  and to LoggingMessageNotification

This ensures that absent (null/Optional.empty()) fields are excluded from JSON
serialization, preventing potential serialization issues with these MCP notification types.

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

Author: tzolov

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

@@ -2203,6 +2203,7 @@ public ProgressNotification(String progressToken, double progress, Double total,
 	 * @param uri The updated resource uri.
 	 * @param meta See specification for notes on _meta usage
 	 */
+	@JsonInclude(JsonInclude.Include.NON_ABSENT)
 	@JsonIgnoreProperties(ignoreUnknown = true)
 	public record ResourcesUpdatedNotification(// @formatter:off
 		@JsonProperty("uri") String uri,
@@ -2224,6 +2225,7 @@ public ResourcesUpdatedNotification(String uri) {
 	 * @param data JSON-serializable logging data.
 	 * @param meta See specification for notes on _meta usage
 	 */
+	@JsonInclude(JsonInclude.Include.NON_ABSENT)
 	@JsonIgnoreProperties(ignoreUnknown = true)
 	public record LoggingMessageNotification( // @formatter:off
 		@JsonProperty("level") LoggingLevel level,