Update deploy-on-push.yml

.github/workflows/deploy-on-push.yml

@@ -23,6 +23,6 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip install -r requirements.txt
     - name: Execute mkdocs utility for deployment
       run: python -m mkdocs gh-deploy