Delete old duckdb index files

default/train/partial-index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:dd912ddc9d5dc91d547f69fa169a1e64f23700c8750dac58a51c75af2ebcaa3f
-size 10231754752

default/validation/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:4128d51dabfa958db2cbf2bf7c119c68d39779ad75218240c33ea2139cb25805
-size 7586983936