Update mkdocs-material installation in CI workflow

Author: jamesrwelch

.github/workflows/ci.yml

@@ -46,7 +46,7 @@ jobs:
 ##
 
             - name: Install mkdoce-material-insiders
-              run: pip install git+https://${{secrets.MKDOCS_INSIDERS_TOKEN}}@github.com/squidfunk/mkdocs-material-insiders.git
+              run: pip install mkdocs-material
 
             - name: Checkout maurodatamapper.github.io
               uses: actions/checkout@v4
@@ -72,4 +72,4 @@ jobs:
                   topic: "${{github.repository}}"
                   content: "${{ job.status == 'success' && ':check_mark:' || ':cross_mark:' }} ${{github.repository}} : **${{github.ref}}**\nGitHub Actions build result: **${{ job.status }}**\n${{ github.event.pull_request.html_url || github.event.head_commit.url }}"
 env:
-    GH_TOKEN: ${{ secrets.GH_TOKEN }}
+    GH_TOKEN: ${{ secrets.GH_TOKEN }}