Trying to resolve noble based CI fixes (#96)

* install pytest explicitly

* use python3 module syntax to be more portable

https://stackoverflow.com/questions/39495429/py-test-vs-pytest-command

The command on jammy is pytest-3 awkwardly.

.github/workflows/test.yml

@@ -15,20 +15,24 @@ jobs:
         container: ['ros:iron', 'ros:rolling']
     container: ${{ matrix.container }}
 
+    env:
+      PIP_BREAK_SYSTEM_PACKAGES: 1
+
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
     - name: Install pip
-      run: apt update && apt install -y python3-pip
+      run: apt update && apt install -y python3-pip python3-pytest
 
     - name: Install pip dependencies
       run: |
-       python3 -m pip install --upgrade --upgrade-strategy eager .[test]
+       python3 -m pip install -U pycodestyle flake8 flake8-blind-except flake8-builtins flake8-class-newline flake8-comprehensions flake8-deprecated flake8-docstrings flake8-import-order flake8-quotes
+       python3 -m pip install .[test]
        python3 -m pip freeze
 
     - name: Install apt dependencies
       run: sudo apt update && sudo apt install -y doxygen graphviz
 
     - name: Run tests
-      run: py.test --verbose test
+      run: python3 -m pytest --verbose test