Update duckdb index files

.gitattributes

@@ -147,3 +147,4 @@ default/tex.stackexchange.com/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/codegolf.stackexchange.com/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/elementaryos.stackexchange.com/index.duckdb filter=lfs diff=lfs merge=lfs -text
 default/networkengineering.stackexchange.com/index.duckdb filter=lfs diff=lfs merge=lfs -text
+default/opendata.stackexchange.com/index.duckdb filter=lfs diff=lfs merge=lfs -text

default/opendata.stackexchange.com/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:52c3ae68517b41e205a7e456f21547e692160f1e3af2c3a39b6c554594ead211
+size 2633728