dvc: remove dvc.data, fix imports

tests/func/data/db/test_index.py

@@ -1,9 +1,9 @@
 import pytest
 
-from dvc.data.db import get_index
 from dvc.exceptions import DownloadError, UploadError
 from dvc.fs import LocalFileSystem
 from dvc.utils.fs import remove
+from dvc_data.db import get_index
 from tests.utils import clean_staging