chore: use ESM equivalent of __dirname

Author: dziraf

src/utils/bundle-component.ts

@@ -1,7 +1,10 @@
 import path from 'path';
+import * as url from 'url';
 
 import type { ComponentLoader } from 'adminjs';
 
+const __dirname = url.fileURLToPath(new URL('.', import.meta.url));
+
 export const bundleComponent = (
   loader: ComponentLoader,
   componentName: string