Update duckdb index files

.gitattributes

@@ -139,3 +139,4 @@ cqadupstack-english-corpus/train/index.duckdb filter=lfs diff=lfs merge=lfs -tex
 cqadupstack-english-queries/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 cqadupstack-gaming-qrels/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 cqadupstack-gis-corpus/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+cqadupstack-mathematica-corpus/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

cqadupstack-mathematica-corpus/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f4e6393c8016c2d47f1844bf48147d437625d62ef026dff6aaf2e4c49aa42abf
+size 111947776