Update duckdb index files

.gitattributes

@@ -63,3 +63,4 @@ hotpotqa.original-split/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 hotpotqa.random-split/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 hotpotqa.random-split/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 naturalquestions.original-split/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+naturalquestions.original-split/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

naturalquestions.original-split/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4e519e746444a103bcbf8eabf048a727462c6416f3556c028b92bad38fbf58a4
+size 8663040