Fix conda build action.

Author: domdfcoding

.github/workflows/python_ci_linux.yml

@@ -127,8 +127,14 @@ jobs:
       - name: Checkout 🛎️
         uses: "actions/checkout@v2"
 
+      - name: Setup Python 🐍
+        uses: "actions/setup-python@v2"
+        with:
+          python-version: 3.8
+
       - name: Install dependencies 🔧
         run: |
+          python -m pip install --upgrade pip setuptools wheel
           wget https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh
           bash miniconda.sh -b -p $HOME/miniconda
           chmod +x .ci/actions_deploy_conda.sh