Update duckdb index files

.gitattributes

@@ -53,3 +53,4 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 *.jpeg filter=lfs diff=lfs merge=lfs -text
 *.webp filter=lfs diff=lfs merge=lfs -text
 pietrolesci--pubmed-20k-rct/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+pietrolesci--pubmed-20k-rct/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

pietrolesci--pubmed-20k-rct/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0e12829ac6050d08eec732a8b60427951c52e7e8ee4cac3bcb2803e2d7c8f911
+size 235417600