TLS sig tests failing when OQS_KEM_ENCODERS=ON

[baentsch]

Describe the bug
If OQS_KEM_ENCODERS=ON, tls sig tests fail

To Reproduce
Use OpenSSL version that supports provider-based TLS sig algs (i.e., >= 3.2).

Expected behavior
All tests should pass.

Environment (please complete the following information):

• OS: Ubuntu 22
• OpenSSL version: 3.4.0-dev
• oqsprovider version "main"

Additional context
CI did not catch the bug because the CI image is too far down level and still runs OpenSSL 3.0.2., see log.

[baentsch]

@praveksharma Did you have a chance to look into this or shall I do now that I'm back?

[praveksharma]

I've not made much progress on this, please do @baentsch!

[baentsch]

Problem resolved "somehow". CI test guarding against re-occurrence added in #616.