spotless configuration crash when using convention plugins combined with settings plugins.

- Gradle 8.0.2
- Spotless 6.17.0

Stacktrace:

```
* What went wrong:
A problem occurred configuring root project 'foo'.
> Could not resolve all files for configuration ':spotless1316845977'.
> Cannot resolve external dependency com.facebook:ktfmt:0.43 because no repositories are defined.
Required by:
project :
```

If a convention plugin applies Spotless on the root project and this convention plugin is applied via a settings plugin, I got this crash.

I think there is a warning from Gradle about resolving this configuration in the configuration phase instead of lazily too.

In the root project, it is used `predeclareDepsFromBuildscript()`

If I apply the convention plugin directly instead of being applied by the settings plugin this is not happening.

Gradle 8.0.2 と Spotless 6.17.0 で、root プロジェクトで predeclareDepsFromBuildscript() を使用し、settings plugin を介して convention plugin を適用することでクラッシュを再現します。その構成を convention plugin を直接適用する場合と比較し、configuration-resolution warning を調査します。settings-plugin setup が、リポジトリを早期に要求したり、configuration phase 中に configuration を解決したりせずに正常に構成されれば完了です。

索引モデルが issue の本文から書いたものです。