Update duckdb index files

.gitattributes

@@ -1,3 +1,4 @@
 default/fairytale_qa-train.parquet filter=lfs diff=lfs merge=lfs -text
 default/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
+default/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

default/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a04c1649c6b1f970d4e954429755a66e06b09d7c1dc2c0b7da26778d1ee1265d
+size 18624512