Deprecate Windows OS support

Unfortunately the Winstackers project has been retired because of no
maintainers[1][2], and OpenStack on Windows host is no longer
maintained.

[1] https://lists.openstack.org/pipermail/openstack-discuss/2022-November/031044.html
[2] https://review.opendev.org/c/openstack/governance/+/886880

Change-Id: I1b810d41ae07d2f6ddce4119a89b06a594f10b84

ceilometer/cmd/polling.py

@@ -93,6 +93,8 @@ def main():
     # As a consequence, we can't use oslo_config_glue.setup() on Windows,
     # because cotyledon.ServiceManager objects are not picklable.
     if os.name == 'nt':
+        LOG.warning("Support for Ceilometer on Windows operating systems is"
+                    "deprecated.")
         sm.add(create_polling_service)
     else:
         conf = _prepare_config()

ceilometer/compute/virt/hyperv/inspector.py

@@ -16,6 +16,7 @@
 import collections
 import functools
 import sys
+import warnings
 
 from os_win import exceptions as os_win_exc
 from os_win import utilsfactory
@@ -82,6 +83,9 @@ class HyperVInspector(virt_inspector.Inspector):
         self._utils = utilsfactory.get_metricsutils()
         self._host_max_cpu_clock = self._compute_host_max_cpu_clock()
 
+        warnings.warn('Support for HyperV is deprecated.',
+                      category=DeprecationWarning, stacklevel=3)
+
     def _compute_host_max_cpu_clock(self):
         hostutils = utilsfactory.get_hostutils()
         # host's number of CPUs and CPU clock speed will not change.

releasenotes/notes/deprecate-windows-support-d784b975ce878864.yaml

@@ -0,0 +1,6 @@
+---
+deprecations:
+  - |
+    Support for running Ceilometer in Windows operating systems has been
+    deprecated because of retirement of the Winstackers project. Because of
+    this, Hyper-V inspector is also deprecated.