Update git submodules

* Update oslo.context from branch 'master'
  to 8d44224e52e6b0c607c3df0b20d758ca3ccb4ff8
  - Don't test with setuptools local distutils.
    
    We noticed some aberrations in log level/threshold handling as of
    Setuptools 60.0.0, and the only substantive change for that release[1]
    toggles the default selection for its internal ("local") distutils
    replacement vs the "stdlib" one. For now, toggle the
    SETUPTOOLS_USE_DISTUTILS envvar in our testing back to the old
    value. This should be revisited once logging is handled better in
    Setuptools.
    
    [1] pypa/setuptools#3038
    
    Change-Id: I2eacb9756d9eb9c5d606599f16cdb412007f5854