Update zuul queue configuration

Zuul changed the way in which queues have to be declared [1][2].
We'll update the os-win zuul configuration accordingly.

While at it, we're also dropping the lower constraints job, which
is broken and has already been removed from recent branches.

We're also updating the sphinx requirement to match the one
from the global requirements file, otherwise the requirements job
fails.

[1] https://lists.zuul-ci.org/pipermail/zuul-discuss/2022-May/001801.html
[2] https://lists.openstack.org/pipermail/openstack-discuss/2022-May/028603.html

Change-Id: I9b443aba106df12de5a8d215a0d88843bfecddf7
(cherry picked from commit e18d57e319)

.zuul.yaml

@@ -1,9 +1,7 @@
 - project:
     templates:
       - check-requirements
-      - openstack-lower-constraints-jobs
       - openstack-python-jobs
       - openstack-python3-train-jobs
       - release-notes-jobs-python3
-    gate:
-      queue: os-win
+    queue: os-win

test-requirements.txt

@@ -7,7 +7,8 @@ hacking>=1.1.0,<1.2.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 ddt>=1.0.1 # MIT
 docutils>=0.11 # OSI-Approved Open Source, Public Domain
-sphinx!=1.6.6,!=1.6.7,>=1.6.2 # BSD
+sphinx>=1.8.0,<2.0.0;python_version=='2.7' # BSD
+sphinx>=1.8.0,!=2.1.0;python_version>='3.4'  # BSD
 oslo.config>=5.2.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0
 stestr>=2.0.0 # Apache-2.0