Update to canvg@4 for ESM support

Currently, jsPDF is responsible for most of our compilation warnings (if we disable suppression). We use it in an Angular project, so you can look up the relevant doc page on that here.

One of the warning sources is the usage of canvg version 3, which is not ESM compatible. Updating to version 4 would fix this warning, even though the same warning is still displayed for many of the other dependencies jsPDF uses (core-js, html2canvas, as well as raf & rgbcolor coming in via canvg).