Update CI workflow to use newer action versions

Author: pgleeson

.github/workflows/omv-ci.yml

@@ -18,10 +18,10 @@ jobs:
         engine: [ jNeuroML_Brian2, jNeuroML, jNeuroML_NEURON, jNeuroML_NetPyNE, jNeuroML_EDEN, jNeuroML_validate, jNeuroML_PyNN_NEURON, Brian2 ]  # jNeuroML_Moose disable moose for now  
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
 
     - name: Set up Python  ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version:  ${{ matrix.python-version }}
 
@@ -30,7 +30,7 @@ jobs:
         pip install git+https://github.com/OpenSourceBrain/osb-model-validation
         pip install scipy sympy matplotlib cython pandas tables
 
-        pip install setuptools --upgrade # needed for eden on Python 3.12
+        pip install setuptools==80 # needed for eden on Python 3.12
         
     - name: Run OMV tests on engine ${{ matrix.engine }}
       run: |