Update test matrix

[syntron]

Based on PR #400 / #402 the test matrix needs to check for different settings including a breaking change in OM;

    # test for:
    # * Python 3.10 - oldest supported version
    # * Python 3.12 - changes in OMCSession / OMCPath
    # * Python 3.14 - latest Python version
    python-version: ['3.10', '3.12', '3.14']
    # * Linux using ubuntu-latest
    # * Windows using windows-latest
    os: ['ubuntu-latest', 'windows-latest']
    # * OM 1.25.0 - before changing definition of simulation overrides
    # * OM stable - latest stable version
    # * OM nightly - latest nightly build
    omc-version: ['1.25.0', 'stable', 'nightly']
    # => total of 12 runs for each test