Add -v to ssh-keyscan for real diagnostic output

Plain ssh-keyscan prints nothing on a per-host failure (by design, so
scanning long host lists doesn't spam errors for hosts that are down),
which is why removing 2>/dev/null earlier revealed nothing. -v forces
it to actually report what's failing.

.gitea/workflows/build-deploy.yml

@@ -31,8 +31,8 @@ jobs:
           mkdir -p ~/.ssh
           printf '%s\n' "$DEPLOY_SSH_KEY" > ~/.ssh/deploy_key
           chmod 600 ~/.ssh/deploy_key
-          ssh-keyscan -4 -H git.haemka.in >> ~/.ssh/known_hosts
-          ssh-keyscan -4 -H -p "${DEPLOY_PORT:-22}" "$DEPLOY_HOST" >> ~/.ssh/known_hosts
+          ssh-keyscan -4 -v -H git.haemka.in >> ~/.ssh/known_hosts
+          ssh-keyscan -4 -v -H -p "${DEPLOY_PORT:-22}" "$DEPLOY_HOST" >> ~/.ssh/known_hosts
 
       - name: Fetch theme submodule
         run: |