Subtotals are not appearing in Customizable Summaries with Grouping

[ibrahimGit123]

Before submitting the bug report, please read and check the following items

• [X] This isn't a feature request or a discussion topic (Please use discussions for that)
• [X] I have searched open and closed issues for duplicates
• [X] I have searched the documentation on the Serenity Platform website https://serenity.is/docs/
• [X] I have read the frequently asked questions https://serenity.is/docs/startsharp/faq
• [X] I have searched my problem in the discussions and the old issues https://github.com/serenity-is/Serenity/discussions

What happened?

Subtotals for each Group no longer appear with Customizable Summaries with Grouping

Subtotals would go where the red line is in the image below:

The issue appears in the demo https://demo.serenity.is/Account/Login/?ReturnUrl=%2FAdvancedSamples%2FCustomizableSummaries

This is the same issue as https://github.com/serenity-is/Serenity/issues/6577.

What did you expect to happen?

Subtotals should appear for each grouping

How to reproduce?

Add Custom Summaries with Grouping

What Serenity Nuget Versions are you seeing the problem on? (separated by comma)

6.48

Relevant log output

No response

Serene template version

No response

Sergen version

No response

Code editor

No response

Operating System

No response

Node.js version

No response

TypeScript version

No response

Database type and version

No response

On which device do you see the problem?

No response

On which operating system do you see the problem?

No response

On which browsers do you see the problem?

No response

On what version of the browsers do you see the problem?

No response

Additional information

No response