setup qt libraries for github CI

steps:
- uses: tlambert03/setup-qt-libs@v1

This is a simple action to install libraries necessary to run a Qt desktop environment on linux runners (and do nothing on macos and windows runners).

Currently, this will run something like:

sudo apt-get install -y libegl1 libdbus-1-3 libxkbcommon-x11-0 \
     libxcb-icccm4 libxcb-image0 libxcb-keysyms1 libxcb-randr0 \
     libxcb-render-util0 libxcb-xinerama0 libxcb-xinput0 libxcb-xfixes0 \
     x11-utils libxcb-cursor0 libopengl0 libegl1-mesa

(see https://github.com/tlambert03/setup-qt-libs/blob/main/index.js for current code)

See also:
pyvista/setup-headless-display-action, which additionally prepares both windows and linux for offscreen opengl tests, and, when used with the qt option, can replace this action

to release new version (for maintainers)

1. npm install
2. npm run prepare
3. git commit -am "new version"
4. git tag -a 'vX.X.X' -m 'vX.X.X'
5. git push --follow-tags
6. gh release create vX.X.X --generate-notes