### Summary

The test_real_path_dev_null test fails on OpenIndiana (a Solaris clone) because on illumos (and Solaris) `/dev/null` is a symlink:
```
$ ls -l /dev/null
lrwxrwxrwx 1 root root 27 Mar 31  2015 /dev/null -> ../devices/pseudo/mm@0:null
$
```

### Issue Type

Bug Report

### Component Name

test_vault_editor.py

### Ansible Version

```console
$ ansible --version
ansible [core 2.14.4]
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/marcel/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3.9/vendor-packages/ansible
  ansible collection location = /home/marcel/.ansible/collections:/usr/share/ansible/collections
  executable location = /usr/bin/ansible
  python version = 3.9.16 (main, Feb 19 2023, 15:42:40) [GCC 10.4.0] (/usr/bin/python3.9)
  jinja version = 3.0.3
  libyaml = True
$
```


### Configuration

```console
NA.  Tests are run directly in the source directory after the source tarball is unpacked.
```


### OS / Environment

OpenIndiana

### Steps to Reproduce

```
$ bin/ansible-test units --python 3.9 --python-interpreter /usr/bin/python3.9 --local --color no --verbose
```


### Expected Results

The `test_real_path_dev_null` test either pass or is skipped.

### Actual Results

```console
___________________ TestVaultEditor.test_real_path_dev_null ____________________
[gw0] sunos5 -- Python 3.9.16 /usr/bin/python3.9
self = <units.parsing.vault.test_vault_editor.TestVaultEditor testMethod=test_real_path_dev_null>

    def test_real_path_dev_null(self):
        filename = '/dev/null'
        ve = self._vault_editor()

        res = ve._real_path(filename)
>       self.assertEqual(res, '/dev/null')

test/units/parsing/vault/test_vault_editor.py:509:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/usr/lib/python3.9/vendor-packages/teamcity/diff_tools.py:33: in _patched_equals
    old(self, first, second, msg)
E   AssertionError: '/devices/pseudo/mm@0:null' != '/dev/null'
E   - /devices/pseudo/mm@0:null
E   + /dev/null
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
filename = '-'
        ve = self._vault_editor()
        res = ve._real_path(filename)
        self.assertEqual(res, '-')
    def test_real_path_dev_null(self):
        filename = '/dev/null'
        ve = self._vault_editor()
        res = ve._real_path(filename)
        self.assertEqual(res, '/dev/null')
    def test_real_path_symlink(self):
        self._test_dir = os.path.realpath(self._create_test_dir())
        file_path = self._create_file(self._test_dir, 'test_file', content=b'this is a test file')
        file_link_path = os.path.join(self._test_dir, 'a_link_to_test_file')
        os.symlink(file_path, file_link_path)
        ve = self._vault_editor()
        res = ve._real_path(file_link_path)
        self.assertEqual(res, file_path)