CODEOWNERS: remove the peeps mentioned as CI owners

These owners do not have the bandwidth/energy to do the reviews which
makes PRs stall and this ownership claim flawed.

Follow-up to c04c78ac

.github/CODEOWNERS

 # Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # SPDX-License-Identifier: curl
-
-# Code owners for CI configuration
-## GitHub Actions
-.github/workflows/ @cmeister2 @mback2k
-## AppVeyor
-appveyor.yml @MarcelRaad @mback2k
-tests/appveyor.pm @mback2k
-## Azure Pipelines
-.azure-pipelines.yml @cmeister2 @mback2k
-tests/azure.pm @mback2k