Improve CI

[rstub]

• re-run the vignettes completely (w/o running them on CRAN?)
• some sort of performance testing, maybe using https://github.com/lorenzwalthert/touchstone

[rstub]

It might also be interesting to run the reverse dependency checks via GHA, c.f. https://github.com/dieghernan/tidyterra/blob/main/.github/workflows/revdepcheck.yaml

[rstub]

Do we always have to run the full matrix of OS / R-version?