Delete old duckdb index files

wall_following/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:75b9d8b4e15ab87730dc52f39815a6df5a707cf77eb8010198f02b07de20cace
-size 1585152

wall_following_0/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:70a36611f296f137e2402c173fd9d285860fc785e0fc4785524ca3157b0aa153
-size 1585152

wall_following_1/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:a1fdbc818c5263bb46b9f41bc7b15b33cd43661a0c059c00fe10de761247504a
-size 1585152

wall_following_2/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:67500aa07d909eaf8a490211365dd65a9eadd3755b9e896e1f501f13c36f6498
-size 1585152

wall_following_3/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:9ed03cba82129726c1c84ba0d62b5da50e9dd0246761706a667ba8c6d2602c0f
-size 1585152