Update release.yml

Author: philippeller

.github/workflows/release.yml

@@ -22,7 +22,7 @@ jobs:
           python-version: "3.x"
       - name: Install dependencies
         run: |
-          python -m pip install --upgrade pip
+          python -m pip install "pip<21.3"
           pip install setuptools wheel build
           pip install .
       - name: Build package