Update duckdb index files

.gitattributes

@@ -17,3 +17,4 @@ copa/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 copa/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 copa/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 multirc/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+multirc/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

multirc/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:65baa164e168c4b2585f3a4d9da5221ce2f7d5f75e6e39ec3eaa12356dd97cf1
+size 27275264