Update duckdb index files

.gitattributes

@@ -63,3 +63,4 @@ de-en/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 es-en/partial-test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 es-en/partial-train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 fr-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+ru-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

ru-en/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:a12316ba22d74d34ba6ebb3088696e1a7f0c9e95ea78156cfc31d24fb09bc05c
+size 344731648