Update duckdb index files

.gitattributes

@@ -106,3 +106,4 @@ Genomics-corpus_coref/partial-test/index.duckdb filter=lfs diff=lfs merge=lfs -t
 MIRACL-corpus_coref/partial-test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 ConditionalQA-keyphrases/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 Genomics-keyphrases/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+NaturalQuestions-keyphrases/test/index.duckdb filter=lfs diff=lfs merge=lfs -text

NaturalQuestions-keyphrases/test/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:01af9297465ed35edc2cce2c39fc4c49202b75f9243d0709e17e46b91acb1266
+size 24653824