Update duckdb index files

.gitattributes

@@ -10,3 +10,4 @@ axb/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 boolq/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 boolq/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 boolq/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
+cb/test/index.duckdb filter=lfs diff=lfs merge=lfs -text

cb/test/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4032944c61519100cc17dcf356ad25f3ebed605b057ea292f8eac8e640b4631a
+size 1060864