[BUGFIX] Fix URLs to RSS feeds in Dashboard Widgets

As the www prefix is not used anymore on typo3.org, the
URLs of the RSS feeds are updated in the Dashboard Widgets.

Resolves: #91297
Releases: master
Change-Id: I4ffff83035967b0ba9b7233c82df01651599f103
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64405


Tested-by: Josef Glatz <josefglatz@gmail.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Richard Haeser <richard@maxserv.com>
Reviewed-by: Josef Glatz <josefglatz@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Richard Haeser <richard@maxserv.com>