Pin tailwindcss to v3 to fix rails new

[skipkayhil]

Fixes rails/rails#54575

Many breaking changes were made in v4 that will require changes to cssbundling-rails' Tailwind installer.

This commit temporarily pins Tailwind to v3 to restore rails new' ability to generate new cssbundling-rails applications with Tailwind.

[skipkayhil]

@dhh if you have some time could you review/release this PR or #164 ?

rails new with cssbundling-rails/tailwind is currently broken due to the recently released breaking changes in Tailwind v4.

[dhh]

@flavorjones Seems like the new release busted rails new. Can you either rollback or roll forward with a root fix?

[skipkayhil]

I don't think this is related to tailwindcss-ruby/tailwindcss-rails.

The can't find executable tailwindcss for gem tailwindcss-ruby error is a red-herring due to Tailwind changing their binary from tailwindcss (v3) to @tailwind/cli (v4). Running npx build:css previously would use the tailwindcss binary from the npm package. Since it no longer exists in Tailwind v4, it looks for tailwindcss in the PATH and finds Mise's shim (which would be from tailwindcss-ruby) which leads to the error. But the error is misleading, because in cssbundling-rails we want the npm package running here, not the tailwindcss-ruby executable.

[flavorjones]

Right, what @skipkayhil said. I don't think this is related to the tailwindcss-ruby gem.

[dhh]

Ahh, yes. I see. I've merged 163 and released 1.4.2: https://github.com/rails/cssbundling-rails/releases/tag/v1.4.2