Update duckdb index files

.gitattributes

@@ -277,3 +277,4 @@ cs_id/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 cs_ko/sampled_test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 cs_ko/sampled_validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 cs_ko/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+cs_ko/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

cs_ko/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fffa133371824e920718eac27148cfd330d43fd368d7904cb2c0b744659764b7
+size 97005568