fix(pvt2): migrations from legacy pivot table error when form_data ha…

…ve pieces of pvt2 (apache#24710)

superset/migrations/shared/migrate_viz/base.py

@@ -64,6 +64,12 @@ def _migrate(self) -> None:
         if "viz_type" in self.data:
             self.data["viz_type"] = self.target_viz_type
 
+        # Sometimes visualizations have same keys in the source form_data and rename_keys
+        # We need to remove them from data to allow the migration to work properly with rename_keys
+        for source_key, target_key in self.rename_keys.items():
+            if source_key in self.data and target_key in self.data:
+                self.data.pop(target_key)
+
         rv_data = {}
         for key, value in self.data.items():
             if key in self.rename_keys and self.rename_keys[key] in rv_data: