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##### SUMMARY

The Git module encourages use of `StrictHostKeyChecking=no` with SSH, which makes the connection vulnerable to a MITM attack.

##### ISSUE TYPE

OpenSSH 7.5+ (2017-03-20) added a safer option which automatically accepts the key on first use but will not allow a MITM on subsequent connections: `StrictHostKeyChecking=accept-new` 

https://man.openbsd.org/ssh_config#StrictHostKeyChecking

It would be great if Ansible encouraged use of that mode by default in the documentation and to implement features such as the Git module's [`accept_hostkey`](https://github.com/ansible/ansible/blob/323d2adfcce9a53e906c2c4a40f6ac5fb32a0e68/lib/ansible/modules/git.py#L1103-L1108) feature.

##### ANSIBLE VERSION

```paste below
N/A
```

##### COMPONENT NAME
* `/modules/source_control/git.py`


repo: https://github.com/ansible/ansible-examples.git
    dest: /src/ansible-examples
    refspec: '+refs/pull/*:refs/heads/*'
- name: Create git archive from repo
  ansible.builtin.git:
    repo: https://github.com/ansible/ansible-examples.git
    dest: /src/ansible-examples
    archive: /tmp/ansible-examples.zip
- name: Clone a repo with separate git directory
  ansible.builtin.git:
    repo: https://github.com/ansible/ansible-examples.git
    dest: /src/ansible-examples
    separate_git_dir: /src/ansible-examples.git
- name: Example clone of a single branch
  ansible.builtin.git:
    repo: https://github.com/ansible/ansible-examples.git
    dest: /src/ansible-examples
    single_branch: yes
    version: master
- name: Avoid hanging when http(s) password is missing
  ansible.builtin.git:
    repo: https://github.com/ansible/could-be-a-private-repo
    dest: /src/from-private-repo
  environment:
    GIT_TERMINAL_PROMPT: 0 # reports "terminal prompts disabled" on missing password
    # or GIT_ASKPASS: /bin/true # for git before version 2.3.0, reports "Authentication failed" on missing password
'''
RETURN = '''
after:
    description: Last commit revision of the repository retrieved during the update.