Migrate all samples to eslint 9

Switches all samples to use eslint 9 with flat configs. I've tried to migrate existing settings as much as possible. However our eslint configs were also inconsistent so I've tried to align these too

notebook-renderer-react-sample/src/client/css.d.ts

@@ -1,4 +1,4 @@
 declare module '*.css' {
-	const classes: { [className: string]: string };
+	const classes: Record<string, string>;
 	export = classes;
 }

notebook-renderer-react-sample/src/client/index.tsx

@@ -37,7 +37,6 @@ export const activate: ActivationFunction = context => {
 				ReactDOM.render(<IssuesList info={{ container: node, mime: outputItem.mime, value: outputItem.json(), context }} />, root);
 			});
 		},
-		// eslint-disable-next-line @typescript-eslint/no-unused-vars
 		disposeOutputItem(_outputId) {
 			// Do any teardown here. outputId is the cell output being deleted, or
 			// undefined if we're clearing all outputs.

notebook-renderer-react-sample/src/client/render.tsx

@@ -1,4 +1,3 @@
-/* eslint-disable @typescript-eslint/naming-convention */
 import React from "react";
 import type { RendererContext } from 'vscode-notebook-renderer';
 
@@ -10,7 +9,7 @@ interface IRenderInfo {
 }
 
 interface GitHubIssuesValue {
-	title: string;
+	title: string
 	url: string;
 	body: string;
 }