Delete old duckdb index files

default/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:8f3373222224261792c96bd91cc321e9220946e546254ea37916b7b2cb1f5f19
-size 3862441984

default/train/partial-index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:8df50e5b34d10dca940bd7f148f52cd393c347eb220b8c0d1bd89a339e7fc513
-size 5304758272