Update duckdb index files

.gitattributes

@@ -113,3 +113,4 @@ iwslt2017-nl-it/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-nl-ro/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-it-ro/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-nl-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:e03595179b09efb5052fd5650bf5bfba5427319e77a6dc8120ed42b9bf604b58
+size 1060864