Update duckdb index files

.gitattributes

@@ -101,3 +101,4 @@ Genomics-corpus/partial-test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 MIRACL-corpus/partial-test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 MSMARCO-corpus/partial-test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 ConditionalQA-corpus_coref/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+NaturalQuestions-corpus_coref/test/index.duckdb filter=lfs diff=lfs merge=lfs -text

NaturalQuestions-corpus_coref/test/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:23495b727fc6e12d2d4338063fbdcd49f4ca706d69f0bf03f4106bf96ef4cc8d
+size 2638491648