Update duckdb index files

.gitattributes

@@ -3,3 +3,4 @@ stacked-summaries--stacked-samsum-1024/csv-test.parquet filter=lfs diff=lfs merg
 stacked-summaries--stacked-samsum-1024/csv-validation.parquet filter=lfs diff=lfs merge=lfs -text
 stacked-summaries--stacked-samsum-1024/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
 stacked-summaries--stacked-samsum-1024/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
+stacked-summaries--stacked-samsum-1024/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text

stacked-summaries--stacked-samsum-1024/validation/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1a7a087039b026d0867a4d00d1942f1251770c2f6a7505505655c5abcdfb8497
+size 5779456