Update duckdb index files

.gitattributes

@@ -56,3 +56,4 @@ train[[:space:]](2).json filter=lfs diff=lfs merge=lfs -text
 nc33--MultiSpanQA/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 nc33--MultiSpanQA/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+default/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

default/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2f819ae1a2e31125b23f5f6b537568c1a5943e98261a0b4b610f688839a75645
+size 1847296