Update duckdb index files

.gitattributes

@@ -56,3 +56,4 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 causal-lm--ConvAI/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 causal-lm--ConvAI/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 sha256:6f4d6639d440adc3beb69d8f26e1781a3148670fde723e596ce0f4bd27cbfabb
+size 11022336