Delete old duckdb index files

DocLayNet_2022.08_processed_on_2023.01/test/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:e6529465b12701ea243b89e6ed836cb07f6ca6ae52b4f9d6ede44f6c4ed5e08d
-size 17838080

DocLayNet_2022.08_processed_on_2023.01/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:7a274e013260cac0a9b2d861ebefc8b464b0ef61e66cfe8f78fc7e5219688fb8
-size 256913408

DocLayNet_2022.08_processed_on_2023.01/validation/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:49840a688af65ce6d2c985ce7df9ea5945ef6fb1851e9cc609f9e7e7206fe6a9
-size 24129536