* ci: enable rhel9.0 tests for openssh_cert
* ci: allow openssh_cert second signature algorithm test for versions >8.7
* ci: narrowing condition to not attempt RSA1 signing exclusively on RHEL >=9
* ci: grouping and documenting condition
* Add RHEL 9.0 and FreeBSD 13.1 to CI.
* Add Ubuntu 22.04 and Fedora 36 to CI.
* Switch orders so that root doesn't have a SHA1 signature.
* Skip openssh_cert test on RHEL 9.0.
* Make it possible that pyOpenSSL isn't installed *at all*.
* Work with default.