use test requirements for pypi release

Author: dickscheid

.github/workflows/pyblish-release-to-pypi.yml

@@ -26,8 +26,8 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install flake8 pytest
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        python -m pip install -U .
+        pip install -r requirements-test.txt
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names