On the KDE CI system, the alkimia library is built when pushing commits.

The associated CI job for building the KF5 variant uses "zypper sources-install
mingwxx-libalkimia5" to fetch the required dependencies for building alkimia.   

After switching the base distribution to openSUSE Leap 15.4, this build
pipeline fails (see https://invent.kde.org/office/alkimia/-/pipelines/305602)
because the named package has an indirect dependency on libqt4, which is not
present.

Since this dependency is unnecessary, it should be removed from the named
package.