### Summary

Ansible no longer returns distribution facts for my Amazon Linux 2 instances after #73767.

### Issue Type

Bug Report

### Component Name

setup

### Ansible Version

```console (paste below)
$ ansible --version
ansible [core 2.11.0b2.post0]  (detached HEAD 30c465c1a9) last updated 2021/03/17 18:53:46 (GMT -400)
  config file = /home/ec2-user/ansible-aws-coll/ansible/ansible.cfg
  configured module search path = ['/home/ec2-user/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/ec2-user/tmp/ansible/lib/ansible
  ansible collection location = /home/ec2-user/ansible-aws-coll/ansible/collections
  executable location = /home/ec2-user/tmp/ansible/bin/ansible
  python version = 3.8.5 (default, Feb 18 2021, 01:24:20) [GCC 7.3.1 20180712 (Red Hat 7.3.1-12)]
  jinja version = 2.11.3
  libyaml = True
```


### Configuration

```console (paste below)
$ ansible-config dump --only-changed
DEVEL_WARNING(env: ANSIBLE_DEVEL_WARNING) = False
```


### OS / Environment

Amazon Linux 2

### Steps to Reproduce

```
ansible localhost -m setup | grep distribution
```


### Expected Results

With 78d3810fdf:
```
[WARNING]: No inventory was parsed, only implicit localhost is available
        "ansible_distribution": "Amazon",
        "ansible_distribution_file_parsed": true,
        "ansible_distribution_file_path": "/etc/system-release",
        "ansible_distribution_file_variety": "Amazon",
        "ansible_distribution_major_version": "2",
        "ansible_distribution_release": "NA",
        "ansible_distribution_version": "2",
```

### Actual Results

```console (paste below)
[WARNING]: No inventory was parsed, only implicit localhost is available
```

dist_file_facts['distribution_file_path'] = path
                dist_file_facts['distribution_file_variety'] = name
                break
            if not has_dist_file:
                
                continue
            parsed_dist_file, parsed_dist_file_facts = self._parse_dist_file(name, dist_file_content, path, dist_file_facts)
            
            if parsed_dist_file:
                dist_file_facts['distribution'] = name
                dist_file_facts['distribution_file_path'] = path
                
                
                
                dist_file_facts['distribution_file_variety'] = name
                dist_file_facts['distribution_file_parsed'] = parsed_dist_file
                dist_file_facts.update(parsed_dist_file_facts)
                break
        return dist_file_facts
    
    def parse_distribution_file_Slackware(self, name, data, path, collected_facts):
        slackware_facts = {}
        if 'Slackware' not in data:
            return False, slackware_facts  
        slackware_facts['distribution'] = name
        version = re.findall(r'\w+[.]\w+\+?', data)
        if version:
            slackware_facts['distribution_version'] = version[0]
        return True, slackware_facts
    def parse_distribution_file_Amazon(self, name, data, path, collected_facts):