Update duckdb index files

.gitattributes

@@ -64,3 +64,4 @@ default/encodec_24k_6bps/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/funcodec_en_libritts_16k_gr1nq32ds320/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/funcodec_en_libritts_16k_gr8nq32ds320/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/funcodec_zh_en_16k_nq32ds320/index.duckdb filter=lfs diff=lfs merge=lfs -text
+default/funcodec_en_libritts_16k_nq32ds640/index.duckdb filter=lfs diff=lfs merge=lfs -text

default/funcodec_en_libritts_16k_nq32ds640/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:eb8542bc586413d93c5ab33f7697af9a10389872d71a963bc191bf4789ad3ea5
+size 1060864