### Summary

When running `ansible -m setup host`, reported `ansible_memtotal_mb` fact changes between invocations.
That's because `setup` reads available non-kernel memory, which fluctuates:

https://github.com/ansible/ansible/blob/2797dc644aa8c809444ccac64cad63e0d9a3f9fe/lib/ansible/module_utils/facts/hardware/openbsd.py#L96-L97

To read total available memory, `hw.physmem` key should be used. Refer to the https://man.openbsd.org/sysctl.2 man, `HW_USERMEM` and `HW_PHYSMEM`.

### Issue Type

Bug Report

### Component Name

setup

### Ansible Version

```console
All.

https://github.com/ansible/ansible/blob/devel/lib/ansible/module_utils/facts/hardware/openbsd.py#L97
```


### Configuration

```console
N/A
```


### OS / Environment

OpenBSD 7.0

### Steps to Reproduce

On OpenBSD host, run this few times:

```
ansible -m setup openbsd_host | grep memtotal
```

Total memory value will be fluctuation between calls.

### Expected Results

I expect to see total installed memory.

### Actual Results

```console
N/A
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
mount_facts = {}
        mount_facts['mounts'] = []
        fstab = get_file_content('/etc/fstab')
        if fstab:
            for line in fstab.splitlines():
                if line.startswith('#') or line.strip() == '':
                    continue
                fields = re.sub(r'\s+', ' ', line).split()
                if fields[1] == 'none' or fields[3] == 'xx':
                    continue
                mount_statvfs_info = get_mount_size(fields[1])
                mount_info = {'mount': fields[1],
                              'device': fields[0],
                              'fstype': fields[2],
                              'options': fields[3]}
                mount_info.update(mount_statvfs_info)
                mount_facts['mounts'].append(mount_info)
        return mount_facts
    def get_memory_facts(self):