remove DOCUMENTER_KEY from workflow

Author: mjohnson541

.github/workflows/documentation.yml

@@ -28,6 +28,5 @@ jobs:
       - name: Build and deploy
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # For authentication with GitHub Actions token
-          DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }} # For authentication with SSH deploy key
           DOCUMENTER_DEBUG: true
         run: julia --color=yes --project=docs/ docs/make.jl