test: Use seclevel=0 unconditionally on OpenSSL 3

OpenSSL 3.1 forces TLS v1.1 and less to security level 0 so the security level was lowered in the tests to pass them. There is no need to conditionally lower the limit on OpenSSL 3.1 since the same can be done on 3.0. Both OpenSSL share the same ABI so it nodejs can be compiled again 3.0 and run the tests against 3.1. The latter is used in Debian CI to ensure smooth transition without recompiling.

Remove 3.1 special case and use it unconditionally on the 3 series.