[bug] Unknown encoding: base64url

[Le0X8]

const NodeBuffer = require('node:buffer').Buffer;
const BrowserBuffer = require('buffer/').Buffer;

console.log(NodeBuffer.from('Hello, world!', 'utf8').toString('base64url')); // works
//> 'SGVsbG8sIHdvcmxkIQ'

console.log(BrowserBuffer.from('Hello, world!', 'utf8').toString('base64url')); // fails

Error:

Uncaught TypeError: Unknown encoding: base64url
    slowToString index.js:544
    toString index.js:606
    encode +page.svelte:41
    <anonymous> debugger eval code:1
[index.js:544:31](http://localhost:5173/node_modules/buffer/index.js)
    slowToString index.js:544
    toString index.js:606
    encode +page.svelte:41
    <anonymous> debugger eval code:1

This may break some stuff, so should be fixed soon!

[Le0X8]

@feross please merge #314