Update duckdb index files

.gitattributes

@@ -59,3 +59,4 @@ default/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 original-splits/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+original-splits/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

original-splits/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a6f964b25e4eb55d06046e1097c376479e76cc1624008d696347409ada236498
+size 5779456