Fix: Remove nonexisting parameter from javadoc

Signed-off-by: Łukasz Jernaś <[email protected]>

Author: deejay1

spring-ai-model/src/main/java/org/springframework/ai/chat/metadata/DefaultUsage.java

@@ -91,7 +91,6 @@ public DefaultUsage(Integer promptTokens, Integer completionTokens, Integer tota
 	 * with completionTokens and the legacy format with generationTokens.
 	 * @param promptTokens the number of tokens in the prompt
 	 * @param completionTokens the number of tokens in the completion (new format)
-	 * @param generationTokens the number of tokens in the generation (legacy format)
 	 * @param totalTokens the total number of tokens
 	 * @param nativeUsage the native usage object
 	 * @return a new DefaultUsage instance