refactor(ChatGptService): use java.nio library for file checking

Signed-off-by: Chris Sdogkos <work@chris-sdogkos.com>

Author: christolis

application/src/main/java/org/togetherjava/tjbot/features/chatgpt/ChatGptService.java

@@ -19,7 +19,7 @@
 
 import javax.annotation.Nullable;
 
-import java.io.File;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.time.Duration;
 import java.util.List;
@@ -141,8 +141,7 @@ public Optional<String> uploadFileIfNotExists(Path filePath, FilePurpose purpose
             return Optional.empty();
         }
 
-        File file = filePath.toFile();
-        if (!file.exists()) {
+        if (!Files.notExists(filePath)) {
             logger.warn("Could not find file '{}' to upload to ChatGPT", filePath);
             return Optional.empty();
         }