Update duckdb index files

.gitattributes

@@ -83,3 +83,4 @@ no_nynorsknarc-corefud/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 no_nynorsknarc-corefud/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 pl_pcc-corefud/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 pl_pcc-corefud/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
+ru_rucor-corefud/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

ru_rucor-corefud/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f7c082e1fee7d3ffeb3c17a1db14562414714aebd8b193bc59d1f87b716efac6
+size 13381632