Update duckdb index files

.gitattributes

@@ -64,3 +64,4 @@ de_parcorfull-corefud/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 de_parcorfull-corefud/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 de_potsdamcc-corefud/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 de_potsdamcc-corefud/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+ru_rucor-corefud/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

ru_rucor-corefud/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8f5b568410380bddbbe1260b1cfb1d0bed8f7bc685355186eebdc18f23d7b77b
+size 3682304