Fix newline at end of file in collection-index.yml

Author: abdurriq

_data/collection-index.yml

@@ -1405,4 +1405,4 @@
   maintainer: esimkowitz
   contact: https://github.com/esimkowitz/devcontainer-features/issues
   repository: https://github.com/esimkowitz/devcontainer-features
-  ociReference: ghcr.io/esimkowitz/devcontainer-features
+  ociReference: ghcr.io/esimkowitz/devcontainer-features