Refactor the conflg location variable to use the new config directory value instead

> [!NOTE]
> Migrated from [augurlabs/augur#3547](https://github.com/augurlabs/augur/issues/3547)
> Originally opened by `@MoralCode` on 2026-01-10

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https://github.com/chaoss/augur/blob/f895f0742c124743fc036bf69bf87ae4a21df210/docker-compose.yml#L75-L76

augurlabs/augur#3314 introduced a variable that allows augur config to be read from an `augur.json` file in a configured directory

other parts of augurs codebase have used other config files for other things previously

this issue is about refactoring those older uses to work with the new "config folder" setting and avoid unnecessarily duplicated variables