fix(system_tests): Move no-op savepoints to DatabaseOperations

- Moved  and related methods from  (incorrect location) to  (correct location).
- This ensures Django uses these no-op methods (SELECT 1) instead of generating invalid  SQL for Spanner.
- Kept  in features to maintain the fix for .

Author: sinhasubham

django_spanner/base.py

@@ -244,21 +244,3 @@ def _start_transaction_under_autocommit(self):
         else:
             # transactions in autocommit mode for Django 3.2.
             self.connection.cursor().execute("SELECT 1")
-
-    def savepoint_create_sql(self, sid):
-        """
-        Return the SQL for creating a savepoint.
-        """
-        return "SELECT 1"
-
-    def savepoint_commit_sql(self, sid):
-        """
-        Return the SQL for committing a savepoint.
-        """
-        return "SELECT 1"
-
-    def savepoint_rollback_sql(self, sid):
-        """
-        Return the SQL for rolling back to a savepoint.
-        """
-        return "SELECT 1"

django_spanner/operations.py

@@ -678,3 +678,21 @@ def _get_limit_offset_params(self, low_mark, high_mark):
             # from Cloud Spanner.
             limit -= offset
         return limit, offset
+
+    def savepoint_create_sql(self, sid):
+        """
+        Return the SQL for creating a savepoint.
+        """
+        return "SELECT 1"
+
+    def savepoint_commit_sql(self, sid):
+        """
+        Return the SQL for committing a savepoint.
+        """
+        return "SELECT 1"
+
+    def savepoint_rollback_sql(self, sid):
+        """
+        Return the SQL for rolling back to a savepoint.
+        """
+        return "SELECT 1"