Re: [PATCH 3/5] scalar: remove stale config values

> From: Derrick Stolee <stolee@gmail.com>
>
> These config values were added in the original Scalar contribution,
> d0feac4e8c (scalar: 'register' sets recommended config and starts
> maintenance, 2021-12-03), but were never fully checked for validity in
> the upstream Git project. At the time, Scalar was only intended for the
> contrib/ directory so did not have as rigorous of an investigation.
>
> Each config option has its own justification for removal:
>
> * core.preloadIndex: This value is true by default, now. Removing this
>   causes some changes required to the tests that checked this config
>   value. Use gui.gcwarning=false instead.
>
> * core.fscache: This config does not exist in the core Git project, but
>   is instead a config option for a Git for Windows feature.
>
> * core.multiPackIndex: This config value is now enabled by default, so
>   does not need to be called out specifically. It was originally
>   included to make sure the background maintenance that created
>   multi-pack-indexes would result in the expected performance
>   improvements.
>
> * credential.validate: This option is not something specific to Git but
>   instead an older version of Git Credential Manager for Windows. That
>   software was replaced several years ago by the cross-platform Git
>   Credential Manger so this option is no longer needed to help users who
>   were on that older software.
>
> * pack.useSparse=true: This value is now Git's default as of de3a864114
>   (config: set pack.useSparse=true by default, 2020-03-20) so we don't
>   need it set by Scalar.