chore: Move css-loader and others into devDependencies

[hborchardt]

Fixes #7430.

Some recent PRs (#7142, #7140) introduced the css-loader, style-loader and esbuild-style-plugin as dependencies. However it seems that they should be categorized as devDependencies instead, because they don't end up in the bundle, but are used to create the bundle.

This poses a problem for me, as it causes npm install plotly.js to install significantly more dependencies than necessary.

In order to not install css-loader and its dependencies during a npm install plotly.js, turn them into devDependencies.

[alexcjohnson]

💃 This is great, absolutely these belong in devDependencies, thanks @hborchardt!

[mattrunyon]

I found this right after I opened a ticket about how esbuild-style-plugin can cause type errors as well with default tsconfig options.

#7430 which I proposed moving to dev dep as a fix since that should prevent the dep from installing a deprecated stub for @types/sass

[aweebit]

@alexcjohnson @archmoj is this going to be published soon? And is it possible to backport this to v2?

In Yarn Classic, the fact that style-loader is a regular dependency causes

warning "plotly.js > style-loader@4.0.0" has unmet peer dependency "webpack@^5.27.0".