refactor: no need to inherit in python3 clean the code (#5659)

### What problem does this PR solve?

As title

### Type of change


- [x] Refactoring

Signed-off-by: yihong0618 <zouzou0208@gmail.com>

deepdoc/vision/ocr.py

@@ -122,7 +122,7 @@ def load_model(model_dir, nm):
     return loaded_model
 
 
-class TextRecognizer(object):
+class TextRecognizer:
     def __init__(self, model_dir):
         self.rec_image_shape = [int(v) for v in "3, 48, 320".split(",")]
         self.rec_batch_num = 16
@@ -393,7 +393,7 @@ class TextRecognizer(object):
         return rec_res, time.time() - st
 
 
-class TextDetector(object):
+class TextDetector:
     def __init__(self, model_dir):
         pre_process_list = [{
             'DetResizeForTest': {
@@ -506,7 +506,7 @@ class TextDetector(object):
         return dt_boxes, time.time() - st
 
 
-class OCR(object):
+class OCR:
     def __init__(self, model_dir=None):
         """
         If you have trouble downloading HuggingFace models, -_^ this might help!!