##### SUMMARY
There was an idea that we could call `ansible-inventory` with encrypted variables in `host_vars` and `group_vars`, and have it output the inventory data without decrypting those secrets.

This was possible if, and only if, those folders contained YAML with individual values encrypted.

It seems that that no longer works.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
lib/ansible/cli/inventory.py

##### ANSIBLE VERSION
```
$ ansible --version
[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.
ansible 2.11.0.dev0
  config file = None
  configured module search path = ['/Users/alancoding/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/alancoding/Documents/repos/ansible/lib/ansible
  ansible collection location = /Users/alancoding/.ansible/collections:/usr/share/ansible/collections
  executable location = /Users/alancoding/.virtualenvs/awx_collection/bin/ansible
  python version = 3.7.7 (default, Mar 10 2020, 15:43:03) [Clang 11.0.0 (clang-1100.0.33.17)]
```

##### CONFIGURATION
defaults

##### OS / ENVIRONMENT
N/A


##### STEPS TO REPRODUCE
old example:

https://github.com/AlanCoding/Ansible-inventory-file-examples/tree/master/vault/single_var_file

```
$ tree vault/single_var_file/
vault/single_var_file/
├── group_vars
│   ├── raleigh
│   └── unencrypted
└── inventory.ini

1 directory, 3 files
```

```
$ cat vault/single_var_file/inventory.ini 
[raleigh]
host1
host2
$ cat vault/single_var_file/group_vars/raleigh 
should_be_artemis_here: !vault |
  $ANSIBLE_VAULT;1.2;AES256;alan
  30386264646430643536336230313232653130643332356531633437363837323430663031356364
  3836313935643038306263613631396136663634613066650a303838613532313236663966343433
  37636234366130393131616631663831383237653761373533363666303361333662373664336261
  6136313463383061330a633835643434616562633238383530356632336664316366376139306135
  3534
```

then run

```
ansible-inventory -i vault/single_var_file/inventory.ini --list --export
```

##### EXPECTED RESULTS
Result with Ansible 2.9

```
$ ansible-inventory -i vault/single_var_file/inventory.ini --list --export
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "raleigh",
            "ungrouped"
        ]
    },
    "raleigh": {
        "hosts": [
            "host1",
            "host2"
        ],
        "vars": {
            "should_be_artemis_here": {
                "__ansible_vault": "$ANSIBLE_VAULT;1.2;AES256;alan\n30386264646430643536336230313232653130643332356531633437363837323430663031356364\n3836313935643038306263613631396136663634613066650a303838613532313236663966343433\n37636234366130393131616631663831383237653761373533363666303361333662373664336261\n6136313463383061330a633835643434616562633238383530356632336664316366376139306135\n3534"
            }
        }
    }
}
```


##### ACTUAL RESULTS
Result with Ansible devel (just rebased 30 min ago)

```
$ ansible-inventory -i vault/single_var_file/inventory.ini --list --export -vvvvv
[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.
ansible-inventory 2.11.0.dev0
  config file = None
  configured module search path = ['/Users/alancoding/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/alancoding/Documents/repos/ansible/lib/ansible
  ansible collection location = /Users/alancoding/.ansible/collections:/usr/share/ansible/collections
  executable location = /Users/alancoding/.virtualenvs/awx_collection/bin/ansible-inventory
  python version = 3.7.7 (default, Mar 10 2020, 15:43:03) [Clang 11.0.0 (clang-1100.0.33.17)]
No config file found; using defaults
setting up inventory plugins
host_list declined parsing /Users/alancoding/Documents/repos/ansible-inventory-file-examples/vault/single_var_file/inventory.ini as it did not pass its verify_file() method
script declined parsing /Users/alancoding/Documents/repos/ansible-inventory-file-examples/vault/single_var_file/inventory.ini as it did not pass its verify_file() method
auto declined parsing /Users/alancoding/Documents/repos/ansible-inventory-file-examples/vault/single_var_file/inventory.ini as it did not pass its verify_file() method
yaml declined parsing /Users/alancoding/Documents/repos/ansible-inventory-file-examples/vault/single_var_file/inventory.ini as it did not pass its verify_file() method
Parsed /Users/alancoding/Documents/repos/ansible-inventory-file-examples/vault/single_var_file/inventory.ini inventory source with ini plugin
ERROR! Attempting to decrypt but no vault secrets found
```

The initial thought was that https://github.com/ansible/ansible/pull/70607 might be the cause, which to be fair, I was warned about. However, a test revert of a9adb754ec3958a0255d1f99d6c54dc274146c50 shows that the error persists.

I don't know what else changed which might have caused the change in behavior. We just got our testing back up and running with Ansible `devel`, and this is an issue discovered from that, so all I can say is that something changed post 2.9.
from __future__ import absolute_import, division, print_function
__metaclass__ = type
import os
import json
import pytest
from datetime import date, datetime
from pytz import timezone as tz
from ansible.module_utils.common._collections_compat import Mapping
from ansible.parsing.ajson import AnsibleJSONEncoder, AnsibleJSONDecoder
from ansible.parsing.yaml.objects import AnsibleVaultEncryptedUnicode
from ansible.utils.unsafe_proxy import AnsibleUnsafeText
def test_AnsibleJSONDecoder_vault():