Previously, the "classifier" attribute was only used to determine the
target classifier of the repackaged archive, always using the main
artifact as the source.
This commit changes the semantic of the attribute so that an existing
archive matching the "classifier" attribute can be used as source,
replacing the archive the same way the goal replaces the main archive
if no classifier is found.
If no artifact with the specified classifier exists, the repackaged
archive is still processed based on the main archive and attached to
the lifecycle using the value of the classifier attribute.
See gh-11061
3c8e012411