### Summary

Based on feedback from a mastodon ansible user:

The first example of https://docs.ansible.com/ansible/latest/collections/ansible/builtin/apt_key_module.html#examples (the apt_key replacement) shows how a pgp key is downloaded and declared as trusted for a repository, but there is no validation of the key going on. Maybe the get_url task could include the checksum argument, to show that (and how) the key should be validated against a known good. Further down there is also an example of apt_key downloading a key without the id argument specified.

### Issue Type

Documentation Report

### Component Name

apt_key

### Ansible Version

```console
$ ansible --version
2.15
```


### Configuration

```console
# if using a version older than ansible-core 2.12 you should omit the '-t all'
$ ansible-config dump --only-changed -t all
none
```


### OS / Environment

none

### Additional Information

The examples all use https URLs, so they do not expose you to just arbitrary MITM; but many projects use untrusted public mirrors to distribute packages and public keys, and instead post the fingerprint of the public key on the non-mirrored first-party website. You are then supposed to verify the downloaded key against that fingerprint (unfortunately a manual action since they post a PGP fingerprint and not a checksum), in order to protect against rogue mirror operators (AFAIK).

### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
found = []
    lines = to_native(output).split('\n')
    for line in lines:
        if (line.startswith("pub") or line.startswith("sub")) and "expired" not in line:
            try:
                
                tokens = line.split()
                code = tokens[1]
                (len_type, real_code) = code.split("/")
            except (IndexError, ValueError):
                
                try:
                    tokens = line.split(':')
                    real_code = tokens[4]
                except (IndexError, ValueError):
                    
                    continue
            found.append(real_code)
    if found and short_format:
        found = shorten_key_ids(found)
    return found
def all_keys(module, keyring, short_format):