.bun-version is a convention similar to .node-version, used to specify the Bun version:
  1. Official Bun GitHub Actions action https://github.com/oven-sh/setup-bun#using-version-file
  2. Renovate bot https://github.com/renovatebot/renovate/issues/29941
Render already supports .node-version file:
Would be great if Bun version support could also be extended to support the .bun-version file: