v3 -> v4 upgrade tool should replace outline with outline-solid

[obecker]

What version of Tailwind CSS are you using?

v3.4.17

What build tool (or framework if it abstracts the build tool) are you using?

vite 6.0.11

What version of Node.js are you using?

v22.11.0

What browser are you using?

N/A

What operating system are you using?

macOS

Describe your issue

In tailwindcss v3 the outline class translates to outline-style: solid;.
https://v3.tailwindcss.com/docs/outline-style

In tailwindcss v4 this has been fixed to be consistent with border utility classes, so outline now translates to outline-width: 1px;.
https://tailwindcss.com/docs/outline-width

That means, when upgrading from v3 to v4 outline should be replaced with outline-solid.
However, running npx @tailwindcss/upgrade@next doesn't do that.

[obecker]

PS: That change is also missing in the upgrade guide. https://tailwindcss.com/docs/upgrade-guide