fix build, pin mkdocs material commit, error in most recent release

Author: zachferland

.github/workflows/deploy.yml

@@ -18,7 +18,7 @@ jobs:
         with:
           python-version: 3.x
       - name: Install MkDocs Material Insiders
-        run: pip install git+https://${INSIDERS_GITHUB_TOKEN}@github.com/squidfunk/mkdocs-material-insiders.git
+        run: pip install git+https://${INSIDERS_GITHUB_TOKEN}@github.com/squidfunk/mkdocs-material-insiders.git@910f9e6e93520e511ba3c5098f2654df58ee7748
       - name: Install plugins
         run: pip install mkdocs-minify-plugin mkdocs-redirects
       - name: Deploy docs