Remove unused css-loader dependency

[rajsite]

Pull Request

🤨 Rationale

The renovate major update in https://github.com/ni/nimble/pull/2226 attempted to update the css-loader library which is not used by nimble-components.

👩‍💻 Implementation

Removed the libary.

🧪 Testing

Rely on CI.

✅ Checklist

• [x] I have updated the project documentation to reflect my changes or determined no changes are needed.

[jattasNI]

I'm going to wait a little while to submit #2234 so don't fret about avoiding conflicts with that, feel free to complete this first.