Hello everyone, this is the corrected patch incorporating suggestions
from Philip and Stefan.  I also changed "activated" to "loaded", as
the latter is more accurate for marking packages in the "Other
versions" section.

I’m submitting this patch to enhance `describe-package` by adding
information about the currently loaded package and improving the
built-in version check.  Since "Other versions" already displays the
current version of the package, I’ve added a "loaded" marker to
indicate which version is loaded in the current Emacs session.

This patch for `package.el` introduces two improvements:

1. The package menu now compares the built-in version of a package
with the available version.  If the available version is newer, the
status is set to "available"; otherwise, it is marked as "built-in".
This helps users identify when updates are available for built-in
packages.

2. Packages listed in the "Other versions" section are now marked with
", loaded" if they are currently loaded in the Emacs session.  This
provides clarity on which versions are in use.

I’d appreciate your feedback and suggestions for integrating this
corrected patch into the master branch.