pa11y installation dependencies on Linux distros

Trying to run `make pa11y` in a 'clean' Ubuntu environment (i.e. Multipass) leads to the following error:

```
Error: Failed to launch the browser process: Code: 127 stderr: /home/ubuntu/.cache/puppeteer/chrome/linux-148.0.7778.97/chrome-linux64/chrome: error while loading shared libraries: libatk-1.0.so.0: cannot open shared object file: No such file or directory
TROUBLESHOOTING: https://pptr.dev/troubleshooting
at ChildProcess.onClose (/home/ubuntu/docs/_dev/node_modules/@puppeteer/browsers/lib/cjs/launch.js:350:24)
at ChildProcess.emit (node:events:521:24)
at ChildProcess._handle.onexit (node:internal/child_process:295:12)
```

[Puppeteer's troubleshooting page](https://pptr.dev/troubleshooting#chrome-doesnt-launch-on-linux) suggests running:
`ldd /home/ubuntu/.cache/puppeteer/chrome/linux-148.0.7778.97/chrome-linux64/chrome | grep "not found"` and installing those missing. This leads to a decent number (~11) manual installations.

The list that worked for me:
* libasound2t64
* libcairo2
* libcups2t64
* libgbm1
* libxcomposite1
* libxdamage1
* libxfixes3
* libxrandr2
* libatk1.0-0
* libatk-bridge2.0-0
* libpango-1.0-0

While these don't have to be part of the `make pa11y-install` process, it would make life easier if it was included in a manner similar to `pdf-prep-force`. (It would be great to have the npm install handled as well if possible)

Start by locating the make pa11y-install target and comparing its dependency setup with pdf-prep-force. Reproduce make pa11y in a clean Ubuntu Multipass environment, using the reported missing libraries as the baseline. Done means the target installs the required dependencies and npm packages, then launches pa11y successfully.

Written by the indexing model from the issue text.