Update duckdb index files

.gitattributes

@@ -63,3 +63,4 @@ default/encodec_24k/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/dac_16k/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_en_libritts_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:c9ac090b66a84f0ac209c5a79a58e56e8527995ceb42ecf4637348038f34d49a
+size 12070912