Update duckdb index files

.gitattributes

@@ -91,3 +91,4 @@ iwslt2017-ko-en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-ko-en/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-nl-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-nl-en/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+iwslt2017-nl-en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

iwslt2017-nl-en/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6a2cc30cb97d29305d518a6e1caf669dee8c8efac4f282af7d69c0a1873ced5b
+size 1060864