Update duckdb index files

.gitattributes

@@ -5,3 +5,4 @@ airline-sentiment/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 corporate-messaging/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 economic-news/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 political-media-audience/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+political-media-bias/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

political-media-bias/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:b72d187d0b464dd2ef317484d64859b8d6718af2623d7024595ebe93ef891d2f
+size 3158016