fix trainer unittest

Link: https://code.alibaba-inc.com/Ali-MaaS/MaaS-lib/codereview/9970626

    * fix trainer unittest

tests/trainers/test_trainer.py

@@ -17,7 +17,7 @@ from modelscope.metrics.builder import MetricKeys
 from modelscope.models.base import Model
 from modelscope.trainers import build_trainer
 from modelscope.trainers.base import DummyTrainer
-from modelscope.utils.constant import LogKeys, ModeKeys, ModelFile
+from modelscope.utils.constant import LogKeys, ModeKeys, ModelFile, Tasks
 from modelscope.utils.test_utils import create_dummy_test_dataset, test_level
 
 
@@ -67,6 +67,7 @@ class TrainerTest(unittest.TestCase):
     @unittest.skipUnless(test_level() >= 1, 'skip test in current test level')
     def test_train_0(self):
         json_cfg = {
+            'task': Tasks.image_classification,
             'train': {
                 'work_dir':
                 self.tmp_dir,
@@ -141,6 +142,7 @@ class TrainerTest(unittest.TestCase):
     @unittest.skipUnless(test_level() >= 1, 'skip test in current test level')
     def test_train_1(self):
         json_cfg = {
+            'task': Tasks.image_classification,
             'train': {
                 'work_dir':
                 self.tmp_dir,
@@ -201,6 +203,7 @@ class TrainerTest(unittest.TestCase):
     @unittest.skipUnless(test_level() >= 1, 'skip test in current test level')
     def test_train_with_default_config(self):
         json_cfg = {
+            'task': Tasks.image_classification,
             'train': {
                 'work_dir': self.tmp_dir,
                 'dataloader': {
@@ -319,6 +322,7 @@ class TrainerTest(unittest.TestCase):
     @unittest.skipUnless(test_level() >= 1, 'skip test in current test level')
     def test_train_with_iters_per_epoch(self):
         json_cfg = {
+            'task': Tasks.image_classification,
             'train': {
                 'work_dir': self.tmp_dir,
                 'dataloader': {