RGB functions do not support real numbers

Issue

RGB colors that contain a real number are not supported, while in browsers this works. The official spec defines real numbers as a valid argument for the modern spec and browsers have supported this for several years so it would be nice to have consistency.

Steps to Reproduce

const { Canvas } = require('canvas');
const canvas = new Canvas();
const ctx = canvas.getContext('2d');

ctx.fillStyle = 'rgb(127,127.0,255)';
console.log(ctx.fillStyle); // output: #000000

ctx.fillStyle = 'rgb(127,127,255)';
console.log(ctx.fillStyle); // output: #7f7fff

I think this parsing may just have to be changed to floats?

Your Environment

• Version of node-canvas: canvas@2.11.2
• Environment: node v20.2.0 on macOS 14.2.1 (e.g. node 20.9.0 on macOS 14.1.1):