Remove deprecated systemProperties configuration option for surefire plugin

Latest Maven 3.9 started to report deprecated configuration used by plugins, we have one of these in wildfly/wildfly-core:

[INFO] --- surefire:2.22.2:test (default-test) @ wildfly-protocol ---
[WARNING] Parameter 'systemProperties' is deprecated: Use systemPropertyVariables instead.

So this task is to replace it in project files with the correct systemPropertyVariables configuration as suggested.