Revert "ci: attempt using the doxypypy docker image"

This reverts commit a7187432, and instead
attempts to use alpine with the py3-pip community package

.gitlab-ci.yml

@@ -41,12 +41,12 @@ pylint:
     - find . -type f -name "*.py" | xargs pylint
 
 pages:
-  image: toliak/doxygen-doxypypy
+  image: alpine
   stage: docs
   needs: []
   script:
-#  - apk update && apk add doxygen && apk add --no-cache python3 py3-pip
-#  - python3 -m pip install doxypypy
+  - apk update && apk add doxygen && apk add --no-cache python3 py3-pip
+  - python3 -m pip install doxypypy
   - doxygen .doxyfile
   - mv doc/html/ public/
   artifacts: