ci: install fiveam before compiling passepartout

core-skills.lisp (and other files) have eval-when blocks that
ql:quickload :fiveam during compilation. If fiveam isn't installed
first, the CI fails with MISSING-COMPONENT.

.github/workflows/test.yml

@@ -27,6 +27,10 @@ jobs:
             --load /tmp/quicklisp.lisp \
             --eval '(quicklisp-quickstart:install)'
           rm -f /tmp/quicklisp.lisp
+          sbcl --noinform --non-interactive \
+            --eval '(load (merge-pathnames "quicklisp/setup.lisp" (user-homedir-pathname)))' \
+            --eval '(ql:quickload :fiveam :silent t)' \
+            --eval '(quit)'
 
       - name: Load and verify system
         run: |