ci: attempt to fix finish-build symlink v2

.github/workflows/build.yml

@@ -833,7 +833,7 @@ jobs:
           (
               echo "rm $dir/latest"
               echo "ln -s $dir/${{ github.run_number }} $dir/latest"
-          ) | sftp -i privkey.pem -P ${{ secrets.NICKCHAN_FTP_PORT }} ${{ secrets.NICKCHAN_FTP_HOST }}
+          ) | sftp -i privkey.pem -P ${{ secrets.NICKCHAN_FTP_PORT }} ${{ secrets.NICKCHAN_FTP_HOST }} -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null
           rm -f privkey.pem
 
       - name: Send Discord build message