simplify main test workflow - do not run test_FMIRegression

* these are test for OpenModelica / no specific check for OMPython
* they are run via a cron job
* it increases the runtime of the unittest job

Author: syntron

.github/workflows/Test.yml

@@ -73,7 +73,7 @@ jobs:
           verbose: true
           emoji: true
           job-summary: true
-          custom-arguments: '-v '
+          custom-arguments: '-v --ignore=./tests/test_FMIRegression.py'
           click-to-expand: true
           report-title: 'Test Report'