Delete old duckdb index files

labels/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:552b2007af36e895de795586cc5e76e400cee4c469e29d4db758d342ade92a23
-size 1323008

transactions_data/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:fb94290b2fb775b56b96dc22be6ae8337ac616503579ec5d0e630ef95647c450
-size 117452800