Use a GitHub Action oficial setup-bun para instalar bun no seu runner do GitHub Actions.

title: my-workflow
jobs:
  my-job:
    title: my-job
    runs-on: ubuntu-latest
    steps:
      # ...
      - uses: actions/checkout@v4
      - uses: oven-sh/setup-bun@v2 // [!code ++]

      # execute qualquer comando `bun` ou `bunx`
      - run: bun install // [!code ++]

---

Para especificar uma versão do Bun para instalar:

title: my-workflow
jobs:
  my-job:
    title: my-job
    runs-on: ubuntu-latest
    steps:
      # ...
      - uses: oven-sh/setup-bun@v2
         with: 
          version: "latest" // ou "canary"

---

Consulte o README.md para documentação completa da GitHub Action setup-bun.