[4.0] Add missing token authentication for API to list of core extensions in ExtensionsHelper

[richard67]

Pull Request for Issue #28503 .

Summary of Changes

See the title and the differences in the changed file.

Testing Instructions

See issue #28503 : Update a 3.10 to 4.0-dev. Then go to System > Manage > Extensions and watch the PHP error log (if you log errors into files in your PHP environment).

For reproducing the issue, use a 4.0 nightly build update package or the nightly build custom URL.

For testing this PR, use the update package built for this PR when using Upload&Update in the Joomla Update component, or use the corresponding custom update URL when using the live update of the Joomla Update component:

• Update zip package for this PR https://ci.joomla.org:444/artifacts/joomla/joomla-cms/4.0-dev/28505/downloads/30754/Joomla_4.0.0-beta1-dev+pr.28505-Development-Update_Package.zip
• Custom URL for using Live Update: https://ci.joomla.org:444/artifacts/joomla/joomla-cms/4.0-dev/28505/downloads/30754/pr_list.xml.

Expected result

No PHP notices.

Actual result

PHP Notice: Undefined property: stdClass::$version in \administrator\components\com_installer\tmpl\manage\default.php on line 108

PHP Notice: Undefined property: stdClass::$version in \administrator\components\com_installer\tmpl\manage\default.php on line 124

Documentation Changes Required

None.

[wilsonge]

Thanks!