Upstreaming from https://phabricator.wikimedia.org/T217984

Steps to reproduce:

1. Phorge at 428f9686c4171912ee186ebd919640a7427da768, PHP 8.2.14
2. Go to http://phorge.localhost/maniphest/query/advanced/
3. Set "Closed By" to "Current Viewer" and Search.
4. Copy the resulting query URL
5. Open that URL in an incognito browser window without being logged into Phorge (thus: "Current Viewer" is not set).

Expected results:
An error message which allows the user to potentially understand what went wrong, and allows them to correct.

Actual results:

Unhandled Exception ("PhabricatorTypeaheadInvalidTokenException")
This datasource ("PhabricatorPeopleUserFunctionDatasource") can not evaluate the function "viewer(...)".