[3.33] fix: use x509 certificates for ftp extensions sftp tests

[gansheer]

Closes #8887

The fix from main can't be backported due to net.i2p.crypto:eddsa still being present, so I rollbacked to x509 certificates that worked before.

[gansheer]

Ran it locally against quarkus-platform 3.33, the FTP tests pass.

[JiriOndrusek]

Even though the test coverage is slightly smaller (or different) - switch from SSH to privateKey - for the maintenance branch this approach should be good enough.

[JiriOndrusek]

@gansheer I took the liberty of adding the [3.33] prefix to the PR title - hope that's okay!

[gansheer]

Even though the test coverage is slightly smaller (or different) - switch from SSH to privateKey - for the maintenance branch this approach should be good enough.

TBH I can't do more whitout adding some ugly (and dumb) code to avoid the issue. Next LTS is more stable and has the tests and the feature.

@gansheer I took the liberty of adding the [3.33] prefix to the PR title - hope that's okay!

Sure, should it be the prefered way for a PR targeting non-main version ?

[jamesnetherton]

should it be the prefered way for a PR targeting non-main version

Yes, makes it easier to backport PRs.