Update duckdb index files

.gitattributes

@@ -2,3 +2,4 @@ allenai--multixscience_dense_mean/parquet-validation.parquet filter=lfs diff=lfs
 allenai--multixscience_dense_mean/parquet-test.parquet filter=lfs diff=lfs merge=lfs -text
 allenai--multixscience_dense_mean/parquet-train.parquet filter=lfs diff=lfs merge=lfs -text
 allenai--multixscience_dense_mean/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+allenai--multixscience_dense_mean/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

allenai--multixscience_dense_mean/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8ff2f016edf22517595f1bb0a4870c17a155404ab63cdd392d0038bb9ece1818
+size 138424320