[Stable/Unmaintained Only] Pin to last compatible tag for py3.8

Stable/2023.1 and Unmaintained xena/yoga/zed runs ubuntu-focal
jobs and since with [1] py3.8 pins are dropped from master
upper-constraints, so these branches can no longer use master
constraints with envs running with python3.8.
With this patch pinning tempest to the last compatible tag
for py3.8 i.e 33.0.0[2]

[Xena Only] unmaintained/xena constraints not compatible with
tempest-35.0.0(xena-last) due to [3] so pinning to an older
compatible tag i.e 33.0.0.

Additionally marked ironic-tempest-bios-ipmi-direct-tinyipa
non-voting and removed from gate until this fixed in
ironic.

[1] https://review.opendev.org/c/openstack/requirements/+/925201
[2] https://lists.openstack.org/archives/list/openstack-discuss@\
    lists.openstack.org/thread/FOWV4UQZTH4DPDA67QDEROAESYU5Z3LE/
[3] https://review.opendev.org/c/openstack/tempest/+/821732

Needed-By: https://review.opendev.org/c/openstack/ironic/+/934140
Depends-On: https://review.opendev.org/c/openstack/tempest/+/933716
Depends-On: https://review.opendev.org/c/openstack/tempest/+/934923
Closes-Bug: #2085886
Change-Id: I5e714655ed329ea2c714f918e3dd843ca764c2c4
(cherry picked from commit d5e95cb608e31d45c647cc598d98928c1a7e7b05)

.zuul.yaml

@@ -686,7 +686,8 @@
         - devstack-multinode
         - devstack-unit-tests
         - openstack-tox-bashate
-        - ironic-tempest-bios-ipmi-direct-tinyipa
+        - ironic-tempest-bios-ipmi-direct-tinyipa:
+            voting: false
         - swift-dsvm-functional
         - grenade:
             irrelevant-files:
@@ -739,7 +740,10 @@
             irrelevant-files:
               - ^.*\.rst$
               - ^doc/.*$
-        - ironic-tempest-bios-ipmi-direct-tinyipa
+        # TODO(ykarel): ironic-tempest job is broken in this branch,
+        # so it is set as non-voting in check queue and commented out here
+        # in gate queue until the job gets fixed.
+        # - ironic-tempest-bios-ipmi-direct-tinyipa
         - swift-dsvm-functional
         - grenade:
             irrelevant-files:

stackrc

@@ -304,8 +304,8 @@ REQUIREMENTS_BRANCH=${REQUIREMENTS_BRANCH:-$TARGET_BRANCH}
 
 # Tempest test suite
 TEMPEST_REPO=${TEMPEST_REPO:-${GIT_BASE}/openstack/tempest.git}
-TEMPEST_BRANCH=${TEMPEST_BRANCH:-$BRANCHLESS_TARGET_BRANCH}
-TEMPEST_VENV_UPPER_CONSTRAINTS=${TEMPEST_VENV_UPPER_CONSTRAINTS:-master}
+TEMPEST_BRANCH=${TEMPEST_BRANCH:-33.0.0 }
+TEMPEST_VENV_UPPER_CONSTRAINTS=${TEMPEST_VENV_UPPER_CONSTRAINTS:-$REQUIREMENTS_DIR/upper-constraints.txt}
 
 
 ##############

tests/test_refs.sh

@@ -15,7 +15,7 @@
 
 echo "Ensuring we don't have crazy refs"
 
-REFS=`grep BRANCH stackrc | grep -v 'TARGET_BRANCH' | grep -v 'NOVNC_BRANCH'`
+REFS=`grep BRANCH stackrc | grep -v 'TARGET_BRANCH' | grep -v 'NOVNC_BRANCH' | grep -v 'TEMPEST_BRANCH'`
 rc=$?
 if [[ $rc -eq 0 ]]; then
     echo "Branch defaults must be one of the *TARGET_BRANCH values. Found:"