backstage release v3.9.5

Fixed

• (agent-platform) Workspace-manager sign-in is granted in muster by @teemow — Workspaces work with workspace-manager 0.10, which moved a person’s provider sign-in to muster: the portal reads the manager’s new sign-in instructions and no longer calls its removed connect and disconnect tools.

Full Changelog: https://github.com/giantswarm/backstage/compare/v3.9.4...v3.9.5