Change the name of the AzureOpenAiTokenizer Bean (#45)

Fix langchain4j/langchain4j#1867

The Bean name is by default the method name, so by changing the method
name we shouldn't have a clash anymore with openAiTokenizer. Also, this
name makes more sense.

langchain4j-azure-open-ai-spring-boot-starter/src/main/java/dev/langchain4j/azure/openai/spring/AutoConfig.java

@@ -154,7 +154,7 @@ AzureOpenAiImageModel openAiImageModel(Properties properties) {
 
     @Bean
     @ConditionalOnMissingBean
-    AzureOpenAiTokenizer openAiTokenizer() {
+    AzureOpenAiTokenizer azureOpenAiTokenizer() {
         return new AzureOpenAiTokenizer();
     }
 }