Update duckdb index files

.gitattributes

@@ -25,3 +25,4 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 *.zip filter=lfs diff=lfs merge=lfs -text
 *.zstandard filter=lfs diff=lfs merge=lfs -text
 *tfevents* filter=lfs diff=lfs merge=lfs -text
+cs-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

cs-en/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c3975fede2cceb1a277a3c43126d871b62518f6846c31f8b50d85edf49587d36
+size 768880640