unstable -> backstage

Author: sabine

data/platform_tools_releases/dune/2025-09-10-dune.3.20.2.md

@@ -6,7 +6,7 @@ tags:
 authors:
 contributors:
 versions:
-unstable: false
+backstage: false
 ignore: false
 github_release_tags:
   - 3.20.2