##### SUMMARY
ansible_run_tags documentation says the default is empty ("[]") at https://docs.ansible.com/ansible/latest/reference_appendices/config.html#tags-run

However when running a debug print with no tags specified, we get this output:

```
- name: print tags
  debug:
    msg: "{{ ansible_run_tags }}"
```

```
$ ansible-playbook deploy.yml
```

```

TASK [workstation : print tags] ************************************************************************************************************************************************************************************************************************************************************
task path: /home/gdevenyi/projects/lozano_ansible/roles/workstation/tasks/main.yml:4
ok: [192.168.56.104] => {
    "msg": [
        "all"
    ]
}

```

<!--- HINT: Did you know the documentation has an "Edit on GitHub" link on every page ? -->

##### ISSUE TYPE
- Documentation Report

##### COMPONENT NAME
<!--- Write the short name of the rst file, module, plugin, task or feature below, use your best guess if unsure -->
tag

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.9.9
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. OS version, browser, etc. -->
Ubuntu 18.04
##### ADDITIONAL INFORMATION
<!--- Describe how this improves the documentation, e.g. before/after situation or screenshots -->

<!--- HINT: You can paste gist.github.com links for larger files -->

tags.add(tag.strip())
            options.tags = list(tags)
        
        if hasattr(options, 'skip_tags') and options.skip_tags:
            skip_tags = set()
            for tag_set in options.skip_tags:
                for tag in tag_set.split(u','):
                    skip_tags.add(tag.strip())
            options.skip_tags = list(skip_tags)
        
        if hasattr(options, 'inventory') and not self.SKIP_INVENTORY_DEFAULTS:
            if options.inventory:
                
                if isinstance(options.inventory, string_types):
                    options.inventory = [options.inventory]
                
                options.inventory = [unfrackpath(opt, follow=False) if ',' not in opt else opt for opt in options.inventory]
            else:
                options.inventory = C.DEFAULT_HOST_LIST
        
        
        
        if self.parser.prog in ['ansible-galaxy', 'ansible-vault'] and not options.verbosity:
            verbosity_arg = next(iter([arg for arg in self.args if arg.startswith('-v')]), None)
            if verbosity_arg:
                display.deprecated("Setting verbosity before the arg sub command is deprecated, set the verbosity "
                                   "after the sub command", "2.13", collection_name='ansible.builtin')
                options.verbosity = verbosity_arg.count('v')
        return options
    def parse(self):