ci: temp fix for models test (#2949)

Another temporary fix for the weird store issue that seems to occur only on actions.

tests/unit/test_models.py

@@ -1,4 +1,5 @@
 import os
+import time
 import random
 import string
 from sys import version_info as pyver
@@ -49,6 +50,8 @@ def test_models(tmpdir: "Path"):
     ) as testmodel:
         testmodel1tag = testmodel.tag
 
+    time.sleep(1)
+
     with bentoml.models.create(
         "testmodel",
         module=__name__,