[BUG] service.args is only compatible with FreeBSD

[n-rodriguez]

Your setup

Formula commit hash / release tag

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Pillar / config used

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Bug details

Describe the bug

Since there is no else in service/args/install.sls it breaks.

       ----------
                 ID: prometheus-service-running-node_exporter
           Function: service.running
               Name: node_exporter
             Result: False
            Comment: The following requisites were not found:
                                 require:
                                     sls: prometheus.service.args.install
            Started: 19:36:01.252119
           Duration: 0.006 ms
            Changes:   
       ----------
                 ID: prometheus-service-running-node_exporter
           Function: service.running
               Name: firewalld
             Result: False
            Comment: The following requisites were not found:
                                 require:
                                     sls: prometheus.service.args.install

Steps to reproduce the bug

Expected behaviour

Attempts to fix the bug

Additional context

[n-rodriguez]

@noelmcloughlin thank you!