AvatarProviderUpdate Wizard failing with "invalid identifier" Runtime Exception when executed in Install Tool in TYPO3 9.5.4

[the-coding-owl]

Bug Report

Description

The update wizard for AvatarProviderUpdate can be clicked in the update wizard section of the install tool, after updating an 8.7 instance to 9.5. The wizard crashes with a RuntimeException telling, that the given identifier is invalid. This may have its cause in how the wizard is registered in the ext_localconf.. because the array key does not match the classes namespace (T3G\AgencyPack\Blog\Install\Updates\AvatarProviderUpdate instead of T3G\AgencyPack\Blog\Updates\AvatarProviderUpdate).
https://github.com/TYPO3GmbH/blog/blob/master/ext_localconf.php#L170

Steps to Reproduce

Update an instance from 8.7 to 9.5 and try executing the update wizards afterwards.

Expected behavior:
The update wizard should be executable

Actual behavior:
The wizard crashes with a Runtime Exception

Versions

TYPO3 9.5.4
PHP7.2
Blog 9.1.1