fix: relative import in wizard; capture expected WARNING in corrupted-data test

- wizard: use relative import per pylint_odoo W8150 rule
- test_get_spreadsheet_data_corrupted: use assertLogs to capture the
  expected warning so oca_checklog_odoo doesn't fail the CI run

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: dnplkndll

dms_spreadsheet/tests/test_dms_spreadsheet.py

@@ -157,7 +157,8 @@ def test_write_sets_handler_on_mimetype_change(self):
     def test_get_spreadsheet_data_corrupted(self):
         """Corrupted binary data does not crash — returns empty dict."""
         file = self._make_spreadsheet_file(content=base64.b64encode(b"not valid json"))
-        data = file.get_spreadsheet_data()
+        with self.assertLogs("odoo.addons.dms_spreadsheet.models.dms_file", "WARNING"):
+            data = file.get_spreadsheet_data()
         self.assertEqual(data["spreadsheet_raw"], {})
 
     # ── Wizard ────────────────────────────────────────────────────────────────

dms_spreadsheet/wizard/dms_spreadsheet_create.py

@@ -3,7 +3,7 @@
 
 from odoo import fields, models
 
-from odoo.addons.dms_spreadsheet.models.dms_file import SPREADSHEET_MIMETYPE
+from ..models.dms_file import SPREADSHEET_MIMETYPE
 
 
 class DmsSpreadsheetCreate(models.TransientModel):