Update duckdb index files

.gitattributes

@@ -57,3 +57,4 @@ Deysi--split-imdb/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 Deysi--split-imdb/valid/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+default/valid/index.duckdb filter=lfs diff=lfs merge=lfs -text

default/valid/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:01d701b8060437ae9e08818597c3f879252ca91463f59102ade463dc4a245f9c
+size 24915968