hide admin notices in WordPress.

hide-admin-notices.php

add_action('admin_enqueue_scripts', 'ds_admin_theme_style');
add_action('login_enqueue_scripts', 'ds_admin_theme_style');
function ds_admin_theme_style() {
	if (!current_user_can( 'manage_options' )) {
		echo '<style>.update-nag, .updated, .error, .is-dismissible { display: none; }</style>';
	}
}

Hello Kyzoe,
You could just block it overall in notice by adding the below to the funtion.php file:

{
echo '<style>.wp-core-ui .notice.is-dismissible { display: none; }</style>' ;
}

Works as expected thanks, here is my version. just use in functions file or small plugin.

small plugin: https://github.com/devuri/hide-wp-admin-notices

add_action('admin_enqueue_scripts', function () {
	if ( ! current_user_can( 'manage_options' ) ) {
		echo '<style>.update-nag, .updated, .error, .is-dismissible { display: none; }</style>';
	}
});