Fix broken gate jobs

This patch fixes broken gate jobs by the following two changes:

1: Set GLOBAL_VENV=false
  Set GLOBAL_VENV=false in job definition to fix gate jobs broken by
  devstack change [0].
  This fix is a temporary workaround in reference to the patch of
  neutron-tempest-plugin [1] and will be reverted after the issue
  is resolved.

2: Define constraints file for docs, api-ref and renos
  Right now we are not using any constraints for docs, api-ref and
  releasenotes builds. This has resulted in docs job failures once
  Sphinx 7.2.0 has been released.
  The patch will ensure that constraints are used an we should not
  face similar issue again.
  TOX_CONSTRAINTS_FILE is updated by Release bot once new branch is
  created, so it should always track relevant constraints.

[0] https://review.opendev.org/c/openstack/devstack/+/558930
[1] https://review.opendev.org/c/openstack/neutron-tempest-plugin/+/891550

Related-bug: #2031415
Change-Id: I5dbf931c15215f39dec03f594c21ee225ebe145f

.zuul.yaml

@@ -143,6 +143,8 @@
         OVN_L3_CREATE_PUBLIC_NETWORK: true
         OVN_DBS_LOG_LEVEL: dbg
         Q_ML2_PLUGIN_MECHANISM_DRIVERS: ovn,logger
+        # TODO(ueha): Remove this workarround if the Zuul jobs succeed with GROBAL_VENV=true
+        GLOBAL_VENV: false
       test_matrix_configs: [neutron]
       zuul_work_dir: src/opendev.org/openstack/tacker
     host-vars:
@@ -264,6 +266,8 @@
           L2_AGENT_EXTENSIONS: qos
           ENABLE_CHASSIS_AS_GW: false
           Q_ML2_PLUGIN_MECHANISM_DRIVERS: ovn,logger
+          # TODO(ueha): Remove this workarround if the Zuul jobs succeed with GROBAL_VENV=true
+          GLOBAL_VENV: false
         devstack_services:
           # To override the parent job's definitions.
           tls-proxy: false
@@ -530,6 +534,8 @@
           USE_PYTHON3: true
           ENABLE_CHASSIS_AS_GW: false
           Q_ML2_PLUGIN_MECHANISM_DRIVERS: ovn,logger
+          # TODO(ueha): Remove this workarround if the Zuul jobs succeed with GROBAL_VENV=true
+          GLOBAL_VENV: false
         devstack_services:
           dstat: false
           horizon: false
@@ -568,6 +574,8 @@
         OVN_L3_CREATE_PUBLIC_NETWORK: true
         OVN_DBS_LOG_LEVEL: dbg
         Q_ML2_PLUGIN_MECHANISM_DRIVERS: ovn,logger
+        # TODO(ueha): Remove this workarround if the Zuul jobs succeed with GROBAL_VENV=true
+        GLOBAL_VENV: false
       devstack_local_conf:
         post-config:
           $NEUTRON_DHCP_CONF:

tox.ini

@@ -169,20 +169,22 @@ commands = python ./tools/check_i18n.py ./tacker
 [testenv:docs]
 allowlist_externals =
   sphinx-build
-deps = -r{toxinidir}/doc/requirements.txt
+deps =
+  -r{toxinidir}/doc/requirements.txt
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
 commands =
   sphinx-build -W -b html doc/source doc/build/html
   oslopolicy-sample-generator --config-file=etc/tacker-policy-generator.conf
 
 [testenv:api-ref]
-deps = -r{toxinidir}/doc/requirements.txt
+deps = {[testenv:docs]deps}
 commands =
   rm -rf api-ref/build
   sphinx-build -W -b html -d api-ref/build/doctrees api-ref/source api-ref/build/html
 allowlist_externals = rm
 
 [testenv:releasenotes]
-deps = -r{toxinidir}/doc/requirements.txt
+deps = {[testenv:docs]deps}
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html