security/clamav-lts: Update to 1.4.3

Now that security/clamav is updated to 1.5.0, update this port to
newer version of LTS.

ReleaseNotes: https://blog.clamav.net/2024/08/clamav-140-feature-release-and-clamav.html (1.4.0)
ReleaseNotes: https://blog.clamav.net/2024/09/clamav-141-132-107-and-010312-security.html (1.4.1)
ReleaseNotes: https://blog.clamav.net/2025/01/clamav-142-and-108-security-patch.html (1.4.2)
ReleaseNotes: https://blog.clamav.net/2025/06/clamav-143-and-109-security-patch.html (1.4.3)