Update duckdb index files

.gitattributes

@@ -200,3 +200,4 @@ simuleq/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 simuleq/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 singleop/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 singleop/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+singleop/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

singleop/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4d11d267b480d749cd267efa6c808d2a88679cc98a03ac50d38e95be956ed219
+size 1060864