On Wed, 2020-10-21 at 13:53 -0700, Per Bothner wrote:
debug1: Next authentication method: publickey debug1: Offering public key: /home/bothner/.ssh/id_rsa RSA SHA256:UrZs1kSmA0JMUjJTlkP4Roth6eI8g5rCNiLWj8xX99E agent debug1: send_pubkey_test: no mutual signature algorithm
that looks to be the problem: "no mutual signature algorithm".
The Fedora crypto policies are updated every release, so this is probably what changed. Changing to the LEGACY policy might make it work again, at the cost of reduced security, I guess. See `man update- crypto-policies` (which also documents how you can override the policy for ssh).