Update duckdb index files

.gitattributes

@@ -63,3 +63,4 @@ nl/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 nl/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 nl/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 pl/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+pl/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

pl/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:25546098708215ede4dabd8f55b92fe8738027b201feee032eedb672475c8d52
+size 3420160