Otdfbt

I like Gutenberg a lot, however, the tips at the beginning of each page load
drives me mad. I would like to disable the nagging tips forever and ever via code.

Please don't post "Disable Gutenberg" plugin, I've already seen that. I want to do it via a couple of lines of code in my theme.

There must be a hook, but I couldn't find it.
Thanks for a hint.

Update #1:

After asking from @leymannx I checked how these settings are stored.
It turned out that settings are not permanent, they are saved in the browser as localStorage.

key: WP_DATA_USER_id:
value: {
 "core/nux":
 "preferences":
 "areTipsEnabled":false,
 "dismissedTips":
 
 ,
 //"core/edit-post"
 //...

Update #2:

Gutenberg tips can be disabled by using dispatch('core/nux').disableTips() (NUX package) and action hook enqueue_block_editor_assets.

file functions.php:

function se334561_editor_tips() 

 wp_enqueue_script(
 'se334561-js',
 // --- to use in plugin ---
 // plugins_url('/disable-tips.js', __FILE__),
 get_stylesheet_directory_uri() . '/disable-tips.js',
 array('wp-blocks')
 );

add_action('enqueue_block_editor_assets', 'se334561_editor_tips');

file disable-tips.js:

jQuery(document).ready(function()
 var isVisible = wp.data.select('core/nux').areTipsEnabled()
 if (isVisible) 
 wp.data.dispatch('core/nux').disableTips();
 
);

As @nmr found out this seems to be stored browser-wise only. Though I found a workaround to simply hide it via CSS. Quick and dirty.

functions.php:

// Add backend styles for Gutenberg.
add_action('enqueue_block_editor_assets', 'gutenberg_editor_assets');

function gutenberg_editor_assets() 
 // Load the theme styles within Gutenberg.
 wp_enqueue_style('my-gutenberg-editor-styles', get_theme_file_uri('/assets/gutenberg-editor-styles.css'), FALSE);

assets/gutenberg-editor-styles.css:

.components-popover.nux-dot-tip 
 display: none !important;

Source: Creating theme editor styles for Gutenberg