net-mgmt/zabbix6-server: Update to 6.0.39
This commit has also intermediate fixes between 6.0.38 and 6.0.39 pulled
in.
Release notes: https://www.zabbix.com/rn/rn6.0.39
PR: 285091
(cherry picked from commit 891c2b8c1de5f8bed884c0c89e2ef28cc23e6159)