chore: remove scroll container (#29437)

* remove scroll container

* update docs to remove deprecated stuff

docs/docs/how-to/routing/scroll-restoration.md

@@ -4,7 +4,7 @@ title: Scroll Restoration
 
 Scroll restoration refers to the [`scrollRestoration`](https://developer.mozilla.org/en-US/docs/Web/API/History/scrollRestoration) property on the [`History`](https://developer.mozilla.org/en-US/docs/Web/API/History) API. This property allows restoring a user's scroll position when navigating to a new page.
 
-Gatsby will handle scroll restoration for you in most cases. However, when you render containers that have their own scroll values, those scroll positions are typically lost between page transitions. To solve that, users can use the `useScrollRestoration` hook or the (deprecated) `ScrollContainer` component in their code to tell Gatsby about scroll containers that we should track and restore.
+Gatsby will handle scroll restoration for you in most cases. However, when you render containers that have their own scroll values, those scroll positions are typically lost between page transitions. To solve that, users can use the `useScrollRestoration` hook in their code to tell Gatsby about scroll containers that we should track and restore.
 
 Here is an example of using the `useScrollRestoration` hook to render a list of countries in an overflow `ul` element.
 
@@ -24,24 +24,3 @@ export default function PageComponent() {
   )
 }
 ```
-
-This is an example of using the (deprecated) `ScrollContainer` component with the same code.
-
-```jsx
-import { ScrollContainer } from "gatsby-react-router-scroll"
-import countryList from "../utils/country-list"
-
-export default class PageComponent extends React.Component {
-  render() {
-    return (
-      <ScrollContainer key="page-component-ul-list">
-        <ul style={{ height: 200, overflow: `auto` }}>
-          {countryList.map(country => (
-            <li>{country}</li>
-          ))}
-        </ul>
-      </ScrollContainer>
-    )
-  }
-}
-```

packages/gatsby-react-router-scroll/src/index.ts

@@ -1,3 +1,2 @@
 export { ScrollHandler as ScrollContext } from "./scroll-handler"
-export { ScrollContainer } from "./scroll-container"
 export { useScrollRestoration } from "./use-scroll-restoration"