[ci] do not install pandoc

Author: dnicolodi

.github/workflows/default.yml

@@ -58,7 +58,6 @@ jobs:
       run: |
         sudo apt-get update
         sudo apt-get dist-upgrade -y
-        sudo apt-get install -y pandoc
         sudo apt-get install -y python3-sphinx
         sudo apt-get install -y python3-docutils
     - name: documentation

requirements-test.txt

@@ -1,7 +1,6 @@
 astroid
 docutils
 mypy
-pandoc
 pytest
 pytest-flake8
 pytest-mypy