Update github action workflow files

[jooolia]

Update to Github workflow files pkgdown, R-CMD-check and test-coverage and pkgcheck so that workflows run and pass in Github actions for this package.

R-CMD-check:
Notably there seems to be the known issue when using the Ubuntu action runners that the dependencies for libcurl are problematic. Following the advice here:https://forum.posit.co/t/libraptor2-dev-depends-libcurl4-gnutls-dev-but-it-is-not-installable-in-r-lib-actions-setup-r-dependencies-v2/181572/4 I have edited the R-CMD-check to manually install the dependencies while awaiting this "apt-satisfy" fix (r-lib/pak#591)

pkgdown: changed runner to macos-latest (from ubuntu-latest)

test-coverage: changed runner to macos-latest (from ubuntu-latest)

pkgcheck: removed as could not find a workaround in the time I had to work on this.

Fixes #24 which is blocking ropensci/software-review#590

Please let me know what you think. I will also check with some of the editors to see if there are some other ways to enable the checks to pass.

[salvafern]

Sounds like a good solution until pak is fixed. Thank you so much @jooolia !