(v4) Allow upgrade tool to migrate tailwind tokens even if the main configuration is upgraded

[gerhardsletten]

Use case: You have upgraded your your project, but you have git-branches with files still not upgraded. It would be nice if you could use the upgrade-tool with the force-parameter and update files from you current cli pwd.

Now the cli would abort because the main configuration / package.json is already upgraded:

cd src/my-component <-- this folder and its contents is not yet migrated
npx @tailwindcss/upgrade@next -f
≈ tailwindcss v4.0.2

│ Tailwind CSS v4.0.3 found. The migration tool can only be run on v3 projects. 

Related to the upgrade-guide#using-the-upgrade-tool