add tox installation

Signed-off-by: Ali Maredia <amaredia@redhat.com>

Author: alimaredia

.github/workflows/build-docs.yml

@@ -66,7 +66,12 @@ jobs:
           cache-dependency-path: |
             **/pyproject.toml
             **/requirements*.txt
-      - name: Run tox docs target (expect failure since tox is not present)
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install tox
+
+      - name: Run tox docs target
         run: |
           make docs
       - name: Deploy to GitHub Pages