chore: update to latest @eslint/markdown package and simple xo type in config

Author: som-sm

package.json

@@ -53,7 +53,7 @@
 		"tagged-tag": "^1.0.0"
 	},
 	"devDependencies": {
-		"@eslint/markdown": "^7.5.1",
+		"@eslint/markdown": "^8.0.1",
 		"@sindresorhus/tsconfig": "^8.0.1",
 		"@types/node": "^25.5.0",
 		"@typescript-eslint/parser": "^8.44.0",

xo.config.js

@@ -9,7 +9,7 @@ import {validateJSDocCodeblocksRule} from './lint-rules/validate-jsdoc-codeblock
 import {readmeJSDocSyncRule} from './lint-rules/readme-jsdoc-sync.js';
 import {jsdocCodeblocksProcessor} from './lint-processors/jsdoc-codeblocks.js';
 
-/** @type {Array<import('xo').XoConfigItem | import('@eslint/core').ConfigObject>} */
+/** @type {import('xo').FlatXoConfig} */
 const xoConfig = [
 	{
 		rules: {