* Ubuntu 22.04 (current operating system for GitHub Actions runners for
  'ubuntu-latest') will install pandoc v2.9.2.1 through apt-get which is
  too old for modern versions of nbsphinx. Installing directly from
  binaries provided on GitHub allows a workaround for getting newer versions
  of pandoc on runners until the GitHub Actions runner environment
  updates.
   - Avoids

```
RuntimeWarning: You are using an unsupported version of pandoc (2.9.2.1).
Your version must be at least (2.14.2) but less than (4.0.0).
```

   from nbsphinx.