Update duckdb index files

.gitattributes

@@ -6,3 +6,4 @@ 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-message/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

political-media-message/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:488a6a0aaf4409400509b61d70acc5bd9396a138a4c1ffad6e4af23c327530f8
+size 3158016