WordPress doesn’t use externally hosted jQuery. In fact, as far as I’m aware, WordPress core does not register any externally hosted scripts.
WordPress bundles its own version of jQuery, and you can enqueue the bundled version by just enqueueing the handle jquery:
wp_enqueue_script( 'jquery' );
Or by specifying 'jquery' as a dependency:
wp_enqueue_script( 'my-script', '/path/to/my-script.js', [ 'jquery' ] );
If you enqueue jQuery like that, but it’s still loading an externally hosted version, then your theme or a plugin is either loading its own version separately, or has re-registered jquery with an external version. The easiest way to find the culprit is to deactivate plugins, checking your site after each one, to see if the correct version is loading.