command used (assuming Marianne-Regular.woff2 is in website/public/fonts
dir, taken from the dsfr):
glyphhanger \
--subset="./Marianne-Regular.woff2" \
--formats=woff2 \
--whitelist="DémarchessimplifiéesFranceTransfertGristNotepaddel'ÉtatRDVServicePublicResanaTchapWebConférencedel'ÉtatWebinairedel'ÉtatFermer✕
"
we had feedback where text in the popup was rendered with completely
random characters… adding the unicode range should help?