feat(StylisPlugin): removes stylis plugin (#2156)

BREAKING CHANGE:

Stylis plugin, `import stylisPlugin from '@dnb/eufemia/style/stylis'`, has been removed.

packages/dnb-design-system-portal/src/docs/uilib/about-the-lib/releases/eufemia/v10-info.mdx

@@ -237,6 +237,7 @@ Find the SCSS @mixin `removeFakeFocus` and replace it with `removeFocusRing`.
 - `import { SpacingHelper } from '@dnb/eufemia/shared'` was removed due to low usage. Use one of the [other exported helpers](/uilib/usage/layout/spacing).
 - `import { LocaleProps, DataAttributeTypes, DynamicElement } from '@dnb/eufemia/shared/interfaces'` was removed, and moved to `@dnb/eufemia/shared/types`.
 - `isIE11` and `IS_IE11` is deprecated as we have stopped supporting Internet Explorer (IE).
+- Stylis plugin, `import stylisPlugin from '@dnb/eufemia/style/stylis'`, has been removed.
 
 ## Install
 

packages/dnb-design-system-portal/src/docs/uilib/usage/customisation/styling/polyfill.mdx

@@ -53,8 +53,6 @@ import cssVars from 'css-vars-ponyfill'
 cssVars()
 ```
 
-But on large applications, the polyfill lacks in stability, therefore we made and recommend using the approach by using the Stylis Plugin method. Se examples below.
-
 ### CSS Properties (variables)
 
 You can also import all the main properties as a JavaScript Object:
@@ -63,54 +61,3 @@ You can also import all the main properties as a JavaScript Object:
 import properties from '@dnb/eufemia/style/properties'
 // properties gives you { '--color-sea-green': '#007272', ... }
 ```
-
-### Styled Components
-
-Is supported from v5 of [styled-components](https://www.styled-components.com) and above.
-
-```jsx
-import stylisPlugin from '@dnb/eufemia/style/stylis'
-import { StyleSheetManager } from 'styled-components'
-
-render(
-  <StyleSheetManager stylisPlugins={[stylisPlugin]}>
-    <MyApp />
-  </StyleSheetManager>
-)
-```
-
-#### Add custom properties:
-
-```jsx
-import { withProperties } from '@dnb/eufemia/style/stylis'
-import { StyleSheetManager } from 'styled-components'
-
-const stylisPlugin = withProperties({
-  '--custom-property': 'CSS value',
-})
-
-render(
-  <StyleSheetManager stylisPlugins={[stylisPlugin]}>
-    <MyApp />
-  </StyleSheetManager>
-)
-```
-
-### Emotion
-
-```jsx
-import stylisPlugin from '@dnb/eufemia/style/stylis'
-import { CacheProvider } from '@emotion/react'
-import createEmotionCache from '@emotion/cache'
-
-const emotionCache = createEmotionCache({
-  key: 'my-prefix-key',
-  stylisPlugins: [stylisPlugin],
-})
-
-render(
-  <CacheProvider value={emotionCache}>
-    <MyApp />
-  </CacheProvider>
-)
-```