Compile failures with texlive

[hughjonesd]

Describe the bug

When using texlive, tinytex commands sometimes fail, leading to failures to compile. See rstudio/tinytex#105 (comment) , and https://yihui.name/tinytex/faq/ number 6.

This causes problems with quick_pdf and it may also cause problems with compiling other documents on CRAN-like systems....

Minimal Reproducible Example

quick_pdf(head(mtcars)) # on a usermode texlive system
rhub::check_for_cran()    # comment out some skip_on_cran() calls from e.g. test-yy-end-to-end.R

Expected behavior

Files should build OK, automatically installing packages if need be.

One solution: autodetect if we need usermode = TRUE. Another possibility: don't autoinstall packages, which should make breakages easier to resolve.