Update duckdb index files

.gitattributes

@@ -59,3 +59,4 @@ ILSUM--ILSUM-1.0/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 Hindi/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 Hindi/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 Hindi/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+English/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

English/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:aad9db93936b514d36c6cc01115256934ae4312979329b668dab1ec311d025d9
+size 6828032