I'd appreciate someone with more knowledge about certificates checking if this is a good idea and if I did it correctly. It definitely fixes the issue.
https://codeberg.org/tusky/Tusky/pulls/5427
#tuskydev
https://codeberg.org/tusky/Tusky/pulls/5427
#tuskydev

trust sectigo root certificates to make some servers work on older Android versions
These certificates are from 2021 and not trusted on Android versions that are older. We already do the same with two ISRG/Let's Encrypt certificates for the same reason. Closes https://codeberg.org/tusky/Tusky/issues/5423