remove documentation stage in CI

build/ci/.documentation-ci.yml

-documentation:pdf:
-  before_script:
-    - pwd
-  image:
-    name: pandoc/latex
-    entrypoint:
-    - ''
-  stage: deploy
-  rules:
-    - if: '$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH'
-      changes:
-        - documentation/design/*.md
-  script:
-  - cd documentation/design
-  - pandoc --citeproc --bibliography=bibliography.bib --csl=acm-sig-proceedings.csl
-    --variable papersize=a4paper -s *.md -o documentation.pdf
-  artifacts:
-    paths:
-    - documentation.pdf
-
-.mdbook_common: &rust
-  image: 
-    name: $CI_REGISTRY/danet/internetworking/mdbook:latest
-    entrypoint:
-      - ''
-  stage: deploy
-  script:
-  - mdbook build documentation --dest-dir public
-
-documentation:website:
-  rules:
-    - if: '$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH'
-      changes:
-        - documentation/design/*.md
-  artifacts:
-    paths:
-      - public
-    expire_in: 1 week
-  <<: *rust
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