You have a 3rd party repository enabled which also check for a Database signature of A44C644D792767CED7941AFEABB2075D5F310CF8. since this signature is not valid you’re stuck - kinda. You may do this:
gpg: error retrieving 'info@jonas-strassel.de' via WKD: No data
gpg: error reading key: No data
gpg: error retrieving 'jonas.strassel@manjaro.org' via WKD: No data
gpg: error reading key: No data
gpg: error retrieving 'jonas.strassel@ioki.com' via WKD: No data
gpg: error reading key: No data
gpg: error retrieving 'jo.strassel@gmail.com' via WKD: No data
gpg: error reading key: No data
gpg: refreshing 1 key from hkps://keyserver.ubuntu.com
gpg: key ABB2075D5F310CF8: "Jonas Strassel <info@jonas-strassel.de>" not changed
gpg: Total number processed: 1
gpg: unchanged: 1
the populate part seemed to be inportant, it disabled a certain number of keys.
edit: pamac still doesn’t work. How do I tell pamac the same information that pacman has now?
edit again:
after running sudo pamac update - even without finishing the update that way - pamac gui also got everything it needs to run without issues!