workflows/reusable.yaml: Remove distro from step name

The section header "Run packaging test on ${{ matrix.distro.name }}" doesn't get the distro name expanded in the run log's section header for whatever reason. It only adds redundant and, hence, slightly confusing information, so remove it.
Signed-off-by: Jan Lindemann <jan@janware.com>

.github/workflows/reusable.yaml

@@ -18,7 +18,7 @@ jobs:
       image: ${{ matrix.distro.image }}
 
     steps:
-      - name: Run packaging test on ${{ matrix.distro.name }}
+      - name: Run packaging test
         uses: ci/action-build-package@master
         with:
           distro-name: ${{ matrix.distro.name }}