cicd: removed Zabbix 3.0 unsupported version

Author: cuprumtan

.github/workflows/mamonsu-tests-master.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       matrix:
         docker_os: ['ubuntu:20.04', 'centos:7', 'centos:8']
-        zabbix_version: ['3.0', '4.0', '5.0', '5.4']
+        zabbix_version: ['4.0', '5.0', '5.4']
         pg_version: ['9.6', '10', '11', '12', '13', '14']
 
     steps: