Update duckdb index files

.gitattributes

@@ -85,3 +85,4 @@ MCTaco_event_typical_time_structured/test/index.duckdb filter=lfs diff=lfs merge
 MCTaco_event_typical_time_structured/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 MCTaco_event_typical_time_structured/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 MCTaco_frequency_structured/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+MCTaco_frequency_structured/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

MCTaco_frequency_structured/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a157535bca1308210422a3b8c6f573ed3a1addc4efd8e8f9dff94e31a09b3112
+size 1060864