Update omv-ci.yml

Author: pgleeson

.github/workflows/omv-ci.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [ 2.7, 3.9 ]
+        python-version: [ 3.9 ]
         engine: [ jNeuroML, jNeuroML_NEURON, jNeuroML_validate, jNeuroML_Moose ]
 
     steps: