Remove pip 21.3 from installation candidates for model templates

.github/workflows/model-templates.yml

@@ -36,7 +36,7 @@ jobs:
 
       - name: Install dependencies
         run: |
-          pip install --upgrade pip
+          pip install --upgrade pip!=21.3
           sudo apt -y update && sudo apt install -y libsndfile1-dev
           pip install .[dev]
       - name: Create model files