Tests and build fails due to a canvas error

Code didn't changed at all since previous build, however tests and build are now failing due to a "canvas error", see https://git.laquadrature.net/lqdn-interne/generateur-slogans/-/jobs/3135 / https://git.laquadrature.net/lqdn-interne/generateur-slogans/-/jobs/3136 and https://git.laquadrature.net/lqdn-interne/generateur-slogans/-/jobs/3137