Update duckdb index files

.gitattributes

@@ -25,3 +25,4 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 *.zip filter=lfs diff=lfs merge=lfs -text
 *.zstandard filter=lfs diff=lfs merge=lfs -text
 *tfevents* filter=lfs diff=lfs merge=lfs -text
+plain_text/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

plain_text/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:6034ddc2841e128a2b337b440195ffd093239e51f673721e8b8a07dfeafd3657
+size 3570675712