Delete old duckdb index files

default/sample_test_L1024/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:b98bca14f4ce8817c417fed51740435c13413108ce06eef91c0fb3743e565e43
-size 12857344

default/sample_test_L2048/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:12efeb1d1cf7bf7b5087d919791faebd98b6e82bbf188e3985c41369944e879b
-size 23605248

default/sample_test_L512/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:c82d384a652769db244170b6785e1caec588c503b8a01e561e47425b3a7e5805
-size 7614464