Place in mu-plugins folder

quiet-trigger-warnings.php

<?php

/**
 * Quiet specific trigger warnings.
 *
 * @package Quiet_Trigger_Errors
 *
 * Plugin Name:       Quiet Trigger Errors
 * Plugin URI:        https://gist.github.com/afragen/986ba6046ebea963074283a77cae07fc
 * Description:       Quiet the trigger warnings to the error log.
 * Version:           0.4.2
 * Author:            Andy Fragen
 * License:           MIT
 * Requires at least: 6.7
 * Requires PHP:      8.0
 * Gist Plugin URI:   https://gist.github.com/afragen/986ba6046ebea963074283a77cae07fc
 */


add_filter(
	'doing_it_wrong_trigger_error',
	function ($trigger, $function_name) {
		$func_arr = ['_load_textdomain_just_in_time'];
		if (in_array($function_name, $func_arr, true)) {
			$trigger = false;
		}

		return $trigger;
	},
	10,
	2
);

Your remove_action call does nothing since QueryMonitor is not loaded at that point. Also, the action callback should be an instance method, not a class method.

Here's what worked for me:

add_action('plugin_loaded', function(string $plugin) {
    if (!str_ends_with($plugin, '/query-monitor/query-monitor.php')) {
        return;
    }
    $collector = QM_Collectors::get('doing_it_wrong');
    remove_action('doing_it_wrong', [$collector, 'action_doing_it_wrong_run']);
    remove_filter('doing_it_wrong_trigger_error', [$collector, 'maybe_prevent_error'], 999);
}, 10, 1);

QM recently updated to fix this issue.