Fix testing workflow

Author: sanders41

.github/workflows/testing.yml

@@ -361,8 +361,8 @@ jobs:
       - name: Install Dependencies
         working-directory: ${{ env.WORKING_DIR }}
         run: |
-          && python -m pip install -U pip \
-          && python -m pip install -r requirements-dev.txt
+          python -m pip install -U pip
+          python -m pip install -r requirements-dev.txt
       - name: MyPy
         working-directory: ${{ env.WORKING_DIR }}
         run: mypy .