Karapace version 4.0.0

Karapace has been upgraded to version 4.0.0, bringing important updates and fixes.

Key changes:

• Systemd journal logging: Added support for logging to the systemd journal for easier log management.
• Schema compatibility checks: Introduced a new messages field in the compatibility API, which provides more precise explanations of schema issues.

To be enabled later:

• Protobuf formatter: This release includes preparation for the Protobuf formatter, which will be available in a future update. It will provide more flexibility when handling Protobuf schemas.

For more details, see the Karapace 4.0.0 release notes.