ci(gitlab-ci): apply workaround on entrypoint part

Signed-off-by: Andrei Jiroh Halili <ajhalili2006@andreijiroh.xyz>

.gitlab-ci.yml

 # The Docker image that will be used to build your app
 image:
   name: dock.mau.dev/andreijiroh-dev/docker-images/mkdocs-material:latest
-  entrypoint: [ "/bin/bash" ]
+  entrypoint: ["/bin/bash", "-l", "-c"] # https://gitlab.com/gitlab-org/gitlab-runner/-/issues/2109#note_47480476
 
 stages:
   - test