client/server integration tests broken on main

[cpu]

Recent scheduled CI runs of main are failing the client/server integration test. E.g. https://github.com/rustls/rustls-ffi/actions/runs/15585556506/job/44071708469

[ctz]

looks like some of the test certs have expired:

        Issuer: CN = minica root ca 10a7a0
        Validity
            Not Before: Apr 28 22:50:23 2023 GMT
            Not After : May 28 22:50:23 2025 GMT
        Subject: CN = localhost

will regenerate these.

[cpu]

It might be nice sometime in the future to drop the minica stuff in favour of rcgen to keep from having to dig up Go & a separate tool for this. The test PKI is very vanilla.

[cpu]

Resolved with #572