Update duckdb index files

.gitattributes

@@ -53,3 +53,4 @@ saved_model/**/* filter=lfs diff=lfs merge=lfs -text
 *.jpeg filter=lfs diff=lfs merge=lfs -text
 *.webp filter=lfs diff=lfs merge=lfs -text
 C++/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+CSharp/test/index.duckdb filter=lfs diff=lfs merge=lfs -text

CSharp/test/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:14210d39d445bb95a49b1c12767b42e2c3b541c035fe4a3a1d06695744ac8d74
+size 3158016