Update duckdb index files

.gitattributes

@@ -62,3 +62,4 @@ default/japanese.stackexchange.com_simple/index.duckdb filter=lfs diff=lfs merge
 anime.stackexchange.com/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 anime.stackexchange.com_simple/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 ja.stackoverflow.com/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+ja.stackoverflow.com_simple/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

ja.stackoverflow.com_simple/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:779baf6aa600549a300585b77b3441fbac9e56c953c17faae392ddcad0804e64
+size 202387456