Skip unnecessary pip install commands in the pythonpackage.yml work…

…flow (#1021)

Remove redundant commands in CI workflow

All checks in pythonpackage.yml are run by tox. Manual installation of requirements is unnecessary here, as tox will install and run everything in separate virtual environments.

.github/workflows/pythonpackage.yml

@@ -18,8 +18,6 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install -r requirements.txt
-        pip install -r test-requirements.txt
         pip install tox
     - name: Run tox
       run: tox run -e format
@@ -41,8 +39,6 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install -r requirements.txt
-        pip install -r test-requirements.txt
         pip install tox
     - name: Run tox
       run: tox run -e pep8
@@ -66,8 +62,6 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install -r requirements.txt
-        pip install -r test-requirements.txt
         pip install tox
     - name: Run tox
       run: tox run -e py${{ matrix.python-version[1] }}