Update duckdb index files

.gitattributes

@@ -66,3 +66,4 @@ iwslt2017-en-ko/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-de-en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-en-fr/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 iwslt2017-en-ja/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+iwslt2017-en-ar/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

iwslt2017-en-ar/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:816aed3ff2e139071b558f9784867d5db2d0d49676afe1ad70bad0b65ebeced7
+size 1060864