Security upgrades filter on instance package list returns all packages in security pocket, not just those upgradable

[Kyle Metscher]

When viewing an instance's package list in the 24.04+ UI, the dropdown list for filtering the instance's available/installed packages includes both an "Upgrades" and "Security upgrades" option. Choosing the "Upgrades" filter correctly returns all packages installed on the instance with a higher version number available. However, choosing "Security upgrades" lists all packages that have had a security upgrade, including packages with the latest version installed on the instance, not just those with an upgrade available. This is most apparent by noting entries in the package list with no "available version:" line in the "details" column. Expected behavior in this case would be for this list to be a subset of the "Upgrades" list, i.e. packages in the security pocket with a higher version available than the one installed on the instance.