Add JSON linting (#36192)

Uses https://github.com/eslint/json to lint all JSON and JSONC files in the repo.

eslint.json.config.ts

@@ -0,0 +1,30 @@
+import {defineConfig, globalIgnores} from 'eslint/config';
+import json from '@eslint/json';
+
+export default defineConfig([
+  globalIgnores([
+    '**/.venv',
+    '**/node_modules',
+    '**/public',
+  ]),
+  {
+    files: ['**/*.json'],
+    plugins: {json},
+    language: 'json/json',
+    extends: ['json/recommended'],
+  },
+  {
+    files: [
+      'tsconfig.json',
+      '.devcontainer/*.json',
+      '.vscode/*.json',
+      'contrib/ide/vscode/*.json',
+    ],
+    plugins: {json},
+    language: 'json/jsonc',
+    languageOptions: {
+      allowTrailingCommas: true,
+    },
+    extends: ['json/recommended'],
+  },
+]);