Install TinyTeX

[gaborcsardi]

On demand. Maybe needs a config option? The TeXlive packages also need a config option.

These config options (and others as well) could default to some Config/GHA entries in DESCRIPTION.

[ms609]

This was a roadblock for one of my packages that used pdflatex to compile vignettes.
After much heartache I found an existing action that did all the heavy lifting for win, mac and linux.
Adding the below to rhub.yaml did the trick:

- name: Setup TeX Live
  uses: teatimeguest/setup-texlive-action@v3
  with:
    packages: scheme-basic

It looks like it should be simple to adapt this to allow a user to set their own value of packages.

This step does take 15 mins on first run so should probably be run "on demand" as you suggest (though caching is performed on successful run) .

[gaborcsardi]

We are already installing tinytex on some containers. IDK if all containers should have it, you don't need to build the vignettes to run an asan or valgrind check. AFAIR many containers skip building the vignettes and the pdf manual already.