fix(store): remove store config from forFeature signature with slice

[markostanimirovic]

PR Checklist

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• The commit message follows our guidelines: https://github.com/ngrx/platform/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Documentation has been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

The StoreModule.forFeature signature with FeatureSlice has StoreConfig as the second input argument, but the configuration isn't registered if passed.

Closes #3216

What is the new behavior?

The StoreModule.forFeature signature with FeatureSlice no longer has StoreConfig as the second input argument.

Does this PR introduce a breaking change?

[x] Yes
[ ] No

BREAKING CHANGES:

The `StoreConfig` argument is removed from the `StoreModule.forFeature` signature with `FeatureSlice`.

BEFORE:

The `StoreModule.forFeature` signature with `FeatureSlice` has `StoreConfig` as the second input argument, but the configuration isn't registered if passed.

AFTER:

The `StoreModule.forFeature` signature with `FeatureSlice` no longer has `StoreConfig` as the second input argument.

[ngrxbot]

Preview docs changes for f58d4d8 at https://previews.ngrx.io/pr3218-f58d4d8b/

[timdeschryver]

Should we add a type test here ?

[timdeschryver]

👍