### Summary

Our setuptools constrain in `pyproject.toml` (listed also in `setup.cfg`) is set to `>= 39.2.0` due to the minimum version available at the time on Ubuntu 18.04.

Now that we have a dependency on Python 3.9 as a minimum, that constraint no longer makes sense, as Python 3.9 is not available on 18.04, and the `dist-packages` `setuptools==39.2.0` compat between deadsnakes python3.9 is non-functional.

This would make Ubuntu 20.04 effectively the minimum supported controller.  The `dist-packages` `setuptools==45.2.0` is functional with the `python3.9` package, and works fine with our packaging.  

This doesn't really grant us anything, since we're waiting for the minimum to eventually be `51.0.0` so we can list the `entry_points` in `pyproject.toml`, but no need to list effectively a non-functional lower bounds. 

### Issue Type

Feature Idea

### Component Name

pyproject.toml

### Additional Information

<!--- Paste example playbooks or commands between quotes below -->
```yaml (paste below)

```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
symlink_list = []
    for dirname, directories, filenames in os.walk('.'):
        for filename in filenames:
            path = os.path.join(dirname, filename)
            
            path = path[2:]
            if os.path.islink(path):
                symlink_list.append(path)
    return symlink_list
def main():
    """All of the files in the repository"""
    complete_file_list = []
    for path in sys.argv[1:] or sys.stdin.read().splitlines():
        complete_file_list.append(path)