Fix usage metrics for the MistralAiChatModelIT tests

Author: ilayaperumalg

models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralAiChatModelIT.java

@@ -217,7 +217,7 @@ void functionCallTest() {
 		assertThat(response.getResult().getOutput().getText()).containsAnyOf("30.0", "30");
 		assertThat(response.getMetadata()).isNotNull();
 		assertThat(response.getMetadata().getUsage()).isNotNull();
-		assertThat(response.getMetadata().getUsage().getTotalTokens()).isLessThan(1050).isGreaterThan(800);
+		assertThat(response.getMetadata().getUsage().getTotalTokens()).isLessThan(1050).isGreaterThan(750);
 	}
 
 	@Test
@@ -328,7 +328,7 @@ void streamFunctionCallUsageTest() {
 		logger.info("Response: " + chatResponse);
 		assertThat(chatResponse.getMetadata()).isNotNull();
 		assertThat(chatResponse.getMetadata().getUsage()).isNotNull();
-		assertThat(chatResponse.getMetadata().getUsage().getTotalTokens()).isLessThan(1050).isGreaterThan(800);
+		assertThat(chatResponse.getMetadata().getUsage().getTotalTokens()).isLessThan(1050).isGreaterThan(750);
 	}
 
 	record ActorsFilmsRecord(String actor, List<String> movies) {