Here’s the Violentmonkey version of that uBlock Origin script :
// ==UserScript==
// @name Brighten OpenStreetMap Tiles
// @namespace http://tampermonkey.net/
// @version 0.1
// @description Brighten the OpenStreetMap tiles by removing the brightness filter
// @author You
// @match https://www.openstreetmap.org/*
// @grant GM_addStyle
// ==/UserScript==
(function() {
'use strict';
// Using GM_addStyle to inject CSS (works around CSP restrictions)
GM_addStyle(`
img.leaflet-tile {
filter: brightness(1) !important;
}
`);
})();
Result :