"! Quarto articles require Bootstrap 5." with no quarto articles

[Bisaloo]

#2797 introduced an error in build_quarto_articles() when trying to build quarto articles with bootstrap < 5

But build_quarto_articles() is called unconditionally in build_articles():

pkgdown/R/build-articles.R

Lines 196 to 225 in 8d9cba1

	build_articles <- function(pkg = ".",
	quiet = TRUE,
	lazy = TRUE,
	seed = 1014L,
	override = list(),
	preview = FALSE) {
	pkg <- section_init(pkg, "articles", override = override)
	check_bool(quiet)
	check_bool(lazy)
	check_number_whole(seed, allow_null = TRUE)
	if (nrow(pkg$vignettes) == 0L) {
	return(invisible())
	}
	cli::cli_rule("Building articles")
	build_articles_index(pkg)
	unwrap_purrr_error(purrr::walk(
	pkg$vignettes$name[pkg$vignettes$type == "rmd"],
	build_article,
	pkg = pkg,
	lazy = lazy,
	seed = seed,
	quiet = quiet
	))
	build_quarto_articles(pkg, quiet = quiet)
	preview_site(pkg, "articles", preview = preview)
	}

This means that all packages using bootstrap < 5, even if they don't use quarto, get this error.