[5.1] WebAssetManager: reset sorting state when new item enabled or disabled

[Fedik]

Summary of Changes

WebAsset ignoring newly added assets (without dependencies) after #42661
This PR is fixing it.

Testing Instructions

Apply patch, visit home page, and check for Schema.org markup in source code.

Actual result BEFORE applying this Pull Request

None (except BreadcrumbList)

Expected result AFTER applying this Pull Request

It is there

Link to documentations

Please select:

• Documentation link for docs.joomla.org:
• No documentation changes for docs.joomla.org needed
• Pull Request link for manual.joomla.org:
• No documentation changes for manual.joomla.org needed

[crommie]

Without patch: only breadcrumb stuff
With patch: all schema.org

(Debug switched off)

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[crommie]

I have tested this item ✅ successfully on 3f09ba1

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[Hackwar]

I have tested this item ✅ successfully on 3f09ba1

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[richard67]

RTC

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[LadySolveig]

Thank you @Fedik and and for the speedy testers @crommie @Hackwar ❤️