Using `{{access_overview}}` in `exists` part of manifest could lead to `RecursionError`

[GDay]

The {{access_overview}} variable checks all integrations if they are still active (generally used in the execute part). If this variable is also called in the exists part of the manifest then it will run the same command again and will create an infinite loop.

Example manifest that will trigger this error:

{
    "form": [],
    "exists": {
        "url": "https://chiefonboarding.com",
        "method": "GET",
        "expected": "{{access_overview}}"
    },
    "execute": [
        {
            "url": "https://chiefonboarding.com",
            "data": {
                "user": "{{access_overview}}"
            },
            "method": "POST"
        }
    ]
}

It's extremely unlikely that access_overview will ever be needed in the exists part.

Originally posted here: https://github.com/chiefonboarding/ChiefOnboarding/pull/385#discussion_r1382538779