SectionList shows inconsistent SeparatorComponent behaviour when using inverted

Description

I found that when SectionList is used inverted on mobile, the SectionSeparatorComponent is not rendered correctly. It renders in between items of the same section - while it shouldn't - and it renders double sometimes there as well.

I found that this happens on both Android and iOS with the latest SDKs and frameworks.
On web it appears not to be an issue.

Steps to reproduce

Here is an expo snack that shows the behavior;
https://snack.expo.dev/@natuurhuisje-dev/sectionlist-inverted-separatorcomponent-inconsistency

React Native Version

tested with issue on both 0.79.5 and 0.81

Affected Platforms

Runtime - iOS, Runtime - Android

Output of npx @react-native-community/cli info

I've got an Expo snack, hope this is sufficient.

Stacktrace or Logs

I've got an Expo snack, hope this is sufficient.

MANDATORY Reproducer

https://snack.expo.dev/@natuurhuisje-dev/sectionlist-inverted-separatorcomponent-inconsistency

Screenshots and Videos

No response

リンクされた Expo Snack を実行し、Android と iOS での inverted SectionList の動作を比較します。SectionSeparatorComponent の配置と重複レンダリングに注目してください。現在の作業内容については、リンクされた pull request #53799 を読んでください。完了条件は、同じセクション内の項目間に separator がレンダリングされず、重複もしないことです。