Update duckdb index files

.gitattributes

@@ -87,3 +87,4 @@ iwslt2017-ja-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-ja-en/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-ja-en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-ko-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+iwslt2017-ko-en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

iwslt2017-ko-en/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f699fef4f2a48f7eef47820424c793eae1da23aa3c9e7a8bf3de9c69ef4ff9a2
+size 1060864