Get rid of canvas dependency

[cmahnke]

The canvas dependency has been problematic in the past, especially on platforms where no pre build binaries were supplied. The situation has significantly worsen in the last weeks as Node changing the LTS to 22.11.0.

For a detailed description see:
Automattic/node-canvas#2448
In short:

• The production canvas module hasn't been updated / released since April 2023 (there is prerelease for a newer version)
• Binaries aren't provided suitable for current node LTS version on any platform

Currently PDF.js already has merged a PR to move away from canvas with the next version, see mozilla/pdf.js#15652 (comment)

Please replace the module with a suitable replacement which is under active maintenance / support