ensure deps and Roxygen are up to date before running pkgdown

[infotroph]

• Updates prerequisites for make pkgdocs to ensure Roxygen docs are up to date before running pkgdown. Needed because Pkgdown works from existing Rd pages and does not check whether they're in sync with the source comments.
• The above also works to ensure that all dependencies are up to date, fixing the current proximal cause of CI failure in Rothc: Soil file support + read options from settings file #3788
• Removes each package's docs/ folder from the list of files considered when checking if document, test, check, or install need to run. Otherwise running pkgdown immediately marks everything as needing redocumentation, reinstallation, etc.
• sets lazy = TRUE in the pkgdown::build_site() call, to avoid recompiling pages that haven't changed since the last pkgdown run.

known pkgdown issues not addressed here:

• Issues with capturing warnings from pkgdown, discussed in build_pkgdown.R - build_quietly() can't muffle and resume warnings when using tryCatch #4034
• make pkgdocs currently always rebuilds all package sites, which takes several minutes. It would be nice to refactor it to only update the packages that are out of date.

[divine7022]

LGTM! totally makes sense
droped one tiny inline, not a blocker

[divine7022]

any reason for not using this ?
reads same to me though, since next char is / so there's no $1docs concat risk,
just wanna make sure i am not missing something on second expan

Suggested change

	${1}/docs/%, \
	$1/docs/%, \

[infotroph]

As far as I know* $1 and ${1} will act identically here, I just chose the delimited one on principle -- my rule is that if I'm even starting to ask "is there concat risk here", I add braces rather than think about it.

*(but note I'm saying this without looking anything up; Make variable syntax does differ from shell variable syntax in various weird little ways)

[divine7022]

that's fair, they are identical here so no behaviour change either way