Update duckdb index files

.gitattributes

@@ -56,3 +56,4 @@ flow3rdown--MARS/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 flow3rdown--MARS/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 flow3rdown--MARS/test/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 sha256:45aeadc4686af6b567185d33aa56ec493ffc196bced7f740834e7d1107ef1fb2
+size 1323008