SSH key extraction doesn't work with ssh-import-id

I used ssh-import-id-gh Nilstrieb which results in
/root/.ssh/authorized_keys containing

ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIG0n1ikUG9rYqobh7WpAyXrqZqxQoQ2zNJrFPj12gTpP Nilstrieb@github/87124356 # ssh-import-id gh:Nilstrieb

Then running sed -E 's/^.*((ssh|ecdsa)-[^[:space:]]+)[[:space:]]+([^[:space:]]+)([[:space:]]*.*)$/\1 \3\4/' /root/. ssh/authorized_keys (the sed monster extracted from

nixos-infect/nixos-infect

Line 23 in 9c5b46d

    
           && keys=$(sed -E 's/^.*((ssh|ecdsa)-[^[:space:]]+)[[:space:]]+([^[:space:]]+)([[:space:]]*.*)$/\1 \3\4/' "$trypath") \

) over it returns this:

ssh-import-id gh:Nilstrieb

not exactly what we want.

On Contabo Ubuntu 22.04 running sed (GNU sed) 4.8