fetch-configlet: remove scripts

[ee7]

Closes: #2260

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Should we remove these, @ErikSchierboom? I think we only had them for historical reasons.

With this PR, there's only one mention of fetch-configlet in this repo:

$ git grep --break --heading 'fetch-configlet'
README.md
252:To download the latest version of the `configlet` tool, please run the [`fetch-configlet`](https://github.com/exercism/configlet/blob/main/scripts/fetch-configlet) bash script or the [`fetch-configlet.ps1`](https://github.com/exercism/configlet/blob/main/scripts/fetch-configlet.ps1) PowerShell script (Windows only). At least one of these scripts should already exist in every track repo's `bin` directory - the script will also download `configlet` to this location. You can then sync the tests by running→

[ErikSchierboom]

I think so