Update duckdb index files

.gitattributes

@@ -57,3 +57,4 @@ de-en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 es-en/partial-validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
 de-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text
 fr-en/validation/index.duckdb filter=lfs diff=lfs merge=lfs -text
+cs-en/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

cs-en/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3d915e8bfe8ef220389ac88e7f88f5211c5792126e5aca6b54d23814037379d7
+size 183513088