docs: rm cube from sponsors

Author: dangreen

README.md

@@ -58,12 +58,6 @@ import { Doughnut } from 'react-chartjs-2';
 <Doughnut data={...} />
 ```
 
-Need an API to fetch data? Consider [Cube](https://cube.dev/?ref=eco-react-chartjs), an open-source API for data apps.
-
-<br />
-
-[![supported by Cube](https://user-images.githubusercontent.com/986756/154330861-d79ab8ec-aacb-4af8-9e17-1b28f1eccb01.svg)](https://cube.dev/?ref=eco-react-chartjs)
-
 ## Docs
 
 - [Migration to v4](https://react-chartjs-2.js.org/docs/migration-to-v4)

website/docs/index.mdx

@@ -77,10 +77,6 @@ ChartJS.register(ArcElement, Tooltip, Legend);
 
 To learn more about importing and registering elements see [tree-shaking](https://react-chartjs-2.js.org/docs/migration-to-v4/#tree-shaking).
 
-:::tip Need an API to fetch data?
-Please consider [Cube](https://cube.dev/?ref=eco-react-chartjs), an open-source API for data apps.
-:::
-
 ## Examples
 
 Please see [live examples](/examples).