Disable tests missing aarch64 test services

[mjurc]

Summary

• Disabling syslog tests on aarch64 as the currently used container is
  not multiarch.
• Disabling Spring Cloud Server tests on aarch64 as there's no aarch64
  based container we can use as test service.

Related issues:

• Move syslog tests to use linuxserver/syslog-ng rather than balabit/syslog-ng #2024
• No Spring Cloud Config server container to run as test service on aarch64 #2025

Please select the relevant options.

• Bug fix (non-breaking change which fixes an issue)
• Dependency update
• Refactoring
• Backport
• New scenario (non-breaking change which adds functionality)
• This change requires a documentation update
• This change requires execution against OCP (use run tests phrase in comment)

Checklist:

• Methods and classes used in PR scenarios are meaningful
• Commits are well encapsulated and follow the best practices