TEST: Set solver again to make sure it works

Signed-off-by: Patrick Avery <patrick.avery@kitware.com>

.github/workflows/package.yml

@@ -62,6 +62,7 @@ jobs:
       run: |
           conda activate hexrd
           mkdir output
+          conda config --set solver libmamba
           conda build --override-channels -c conda-forge --output-folder output/ conda.recipe/
       # This is need to ensure ~/.profile or ~/.bashrc are used so the activate
       # command works.