Update duckdb index files

.gitattributes

@@ -63,3 +63,4 @@ ZurichNLP--rsd-ists-2016/test_ko/index.duckdb filter=lfs diff=lfs merge=lfs -tex
 ZurichNLP--rsd-ists-2016/test_zh/index.duckdb filter=lfs diff=lfs merge=lfs -text
 ZurichNLP--rsd-ists-2016/train_es/index.duckdb filter=lfs diff=lfs merge=lfs -text
 ZurichNLP--rsd-ists-2016/train_fr/index.duckdb filter=lfs diff=lfs merge=lfs -text
+ZurichNLP--rsd-ists-2016/train_ja/index.duckdb filter=lfs diff=lfs merge=lfs -text

ZurichNLP--rsd-ists-2016/train_ja/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b0dcda284b99f56b845d317e8947ed7594a2aa778ee5b89246ffbf3bc30ce04f
+size 1585152