some fonts provide extremely long ligatures, e.g. Fira Code for ===================================================
The char atlas code tries to find a row to fit it but fails and gets stuck in an infinite loop

^Here we're checking if there's room on the current row and creating a new one if not.

Details

• Browser and browser version: chrome 108
• OS version: macOS 12
• xterm.js version: 5.1.0 (also on latest master branch)

Steps to reproduce

1. Install Fira Code font, Run the xterm demo and enable ligatures
2. start typing =
3. Keep looking at the char atlas drawn below, once the glyph is almost the same width as char atlas, typing the next = will freeze everything.