### Summary

When running the builtin `known_hosts` module without a `path` argument (thus defaulting to `~/.ssh/known_hosts`), it will fail when `~/.ssh/` does not exist.

https://github.com/ansible/awx/issues/10984

### Issue Type

Documentation Report

### Component Name

known_hosts

### Ansible Version

```console
$ ansible --version
ansible [core 2.12.0.dev0]
  config file = None
  configured module search path = ['/home/runner/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.8/site-packages/ansible
  ansible collection location = /home/runner/.ansible/collections:/usr/share/ansible/collections
  executable location = /usr/local/bin/ansible
  python version = 3.8.6 (default, Jan 29 2021, 17:38:16) [GCC 8.4.1 20200928 (Red Hat 8.4.1-1)]
  jinja version = 2.10.3
  libyaml = True
```


### Configuration

```console
$ ansible-config dump --only-changed
[WARNING]: You are running the development version of Ansible. You should only run Ansible from "devel" if you are modifying the Ansible engine, or trying out features under development.
This is a rapidly changing source of code and can become unstable at any point.
```


### OS / Environment

Docker image quay.io/ansible/awx-ee:latest (Image id 139d0f567124 )

### Steps to Reproduce

<!--- Paste example playbooks or commands between quotes below -->
```sh
bash-4.4$ ansible localhost -m known_hosts -a 'name=example.com key="example.com ssh-rsa test"'
```


### Expected Results

Success & the given key in a new `~/.ssh/known_hosts`

### Actual Results

```console
localhost | FAILED! => {
    "changed": false,
    "msg": "Failed to write to file /home/runner/.ssh/known_hosts: [Errno 2] No such file or directory: '/home/runner/.ssh/tmpkqkq1oke'"
}
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
from __future__ import absolute_import, division, print_function
__metaclass__ = type
DOCUMENTATION = r'''
---
module: known_hosts
short_description: Add or remove a host from the C(known_hosts) file
description:
   - The C(known_hosts) module lets you add or remove a host keys from the C(known_hosts) file.
   - Starting at Ansible 2.2, multiple entries per host are allowed, but only one for each key type supported by ssh.
     This is useful if you're going to want to use the M(ansible.builtin.git) module over ssh, for example.
   - If you have a very large number of host keys to manage, you will find the M(ansible.builtin.template) module more useful.
version_added: "1.9"
options:
  name:
    aliases: [ 'host' ]
    description:
      - The host to add or remove (must match a host specified in key). It will be converted to lowercase so that ssh-keygen can find it.
      - Must match with <hostname> or <ip> present in key attribute.
      - For custom SSH port, C(name) needs to specify port as well. See example section.
    type: str
    required: true
  key:
    description:
      - The SSH public host key, as a string.