Exclude files from tailwind parsing by plugin

[benjaminpreiss]

What version of Tailwind CSS are you using?

3.4.1

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

postcss 8.4.34 svelte 4.2.7, @sveltejs/kit 2.0.0, vite 5.0.3

What version of Node.js are you using?

v18.17.1

What browser are you using?

Brave

What operating system are you using?

macOS

Reproduction URL

https://github.com/frontline-hq/tw-exclude-content

Reproduction steps:

// Install
pnpm i
// run
pnpm run dev

Then visit the app in the browser and check for the file app.css in the network tab.
You will see that it includes the tw class bg-blue-900.

Describe your issue

content configurations returned from tailwind plugins are not respected for excluded file globs.
D.h. the classes in the file should not be included in the css as specified here

[benjaminpreiss]

#12892

[benjaminpreiss]

The same happens with the safelist property - it is simply overwritten by the array present in the config.

I think it should be possible to extend the safelist from a plugin or a preset.