backstage release v2.86.0-rc.2

Added

• (gs,kubernetes-react) Show version, provider and location for CAPZ managed (AKS) clusters in #2677 by @luca-rui
• (agent-platform) Explain failed agents and tighten the agent detail page in #2709 by @marians

Full Changelog: https://github.com/giantswarm/backstage/compare/v2.85.0...v2.86.0-rc.2