Update duckdb index files

.gitattributes

@@ -2,3 +2,4 @@ de/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 de/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 de/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

en/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:7ad718db121dae292f854a658139a395a28d4e1a5376d11081bcfe1f804d8fd9
+size 1323008