Move to ESLint 10 and @microbit/eslint-config 0.2.1 (#26)

Pin the React version the rules key off. eslint-react follows whatever
React resolves in the project, which is 19, but we publish for React
>= 17.0.2: without the pin it flags our forwardRef components, our
Context.Provider and our useContext, none of which our consumers on 17
or 18 can drop.

That leaves one real finding the old plugin never reported: the frame
passed key after the prop spread, which deoptimises the automatic JSX
runtime. Key first. Nothing changes semantically, as a props object
never carries key.

npm cannot resolve this bump in one step. The lockfile pins the old
shared config with its eslint ^9.7 peer and npm tries to reconcile that
rather than replace it, failing with a circular ERESOLVE. Uninstall
eslint and @microbit/eslint-config first, then install the new pair.

Author: microbit-matt-hillsdon

eslint.config.js

@@ -1,4 +1,13 @@
 import microbit from '@microbit/eslint-config/react';
 import storybook from 'eslint-plugin-storybook';
 
-export default [...microbit, ...storybook.configs['flat/recommended']];
+export default [
+  ...microbit,
+  ...storybook.configs['flat/recommended'],
+  {
+    // Rules keyed off the React version follow whatever is installed, which is
+    // 19. We publish for React >= 17.0.2, so pin to the oldest we support
+    // rather than be told to adopt APIs our consumers may not have.
+    settings: { 'react-x': { version: '17.0.2' } },
+  },
+];