Consider running babel-plugin-styled-components if styled-components are in peerDependencies

[stipsan]

Running this plugin if it's not required adds build time. In a lot of cases it's enough to check if styled-components are in devDependencies as well as peerDependencies.

Reasons for why this plugin is good for our libraries, like @sanity/ui are:

https://github.com/styled-components/babel-plugin-styled-components?tab=readme-ov-file#babel-plugin-styled-components

• consistently hashed component classNames between environments (a must for server-side rendering)
• various types of minification for styles and the tagged template literals styled-components uses

Most importantly, it performs dead code elimination:
https://styled-components.com/docs/tooling#dead-code-elimination

Without this plugin sc components that aren't used require analysis to be eliminated by pipelines that use vite, terser, webpack, turbopack or what have you.
With #__PURE__ annotations most tooling knows it's safe to remove the component if nothing imported in userland actually uses it.

Due to how much styled-components are used in @sanity/ui and in sanity itself, the benefits here can be substantial. Both in end user perf due to a smaller browser bundle, but also for cold starts in envs such as next dev.