CI: use absolute path for chocolatey

This commit should be reworked once chocolatey is correctly
installed inside the self-hosted runner. Ftm, the installation
is done through the CI and this patch is required to let the
workflow run smoothly

.github/workflows/full_documentation.yml

@@ -45,9 +45,9 @@ jobs:
           }
 
           # Check if Pandoc is installed
-          if (!(choco list --local-only -r pandoc)) {
+          if (!(C:\ProgramData\chocolatey\bin\choco list --local-only -r pandoc)) {
               # Install Pandoc
-              choco install pandoc -y
+              C:\ProgramData\chocolatey\bin\choco install pandoc -y
           } 
 
       - name: 'Create virtual env'