Delete old duckdb index files

default/test/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:356a5af387a5e8ac1c6fd2d69d69fed6778703a9714175a847bf2845d60bfe9d
-size 1947742208

default/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:3077253e6940fefbb4789466ad5886a6be9d54a5f2423f8183bf3d91e9132b41
-size 4642320384

default/train/partial-index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:b3cea5f424bf44783aab37bbd0eba8cefd212c6981769786a8523b358875e0e8
-size 5110771712