Update TOX_CONSTRAINTS_FILE for stable/2024.2

Update the URL to the upper-constraints file to point to the redirect
rule on releases.openstack.org so that anyone working on this branch
will switch to the correct upper-constraints list automatically when
the requirements repository branches.

Until the requirements repository has as stable/2024.2 branch, tests will
continue to use the upper-constraints list on master.

Change-Id: Icfd9ec1a90af83e190ce501c374f745cfdb94b52

.gitreview

@@ -2,3 +2,4 @@
 host=review.opendev.org
 port=29418
 project=openstack/python-cloudkittyclient.git
+defaultbranch=stable/2024.2

tox.ini

@@ -75,7 +75,7 @@ commands = {posargs}
 
 [testenv:docs]
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2024.2}
   -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build --keep-going -b html doc/source doc/build/html
 
@@ -101,7 +101,7 @@ import_exceptions = cloudkittyclient.i18n
 
 [testenv:releasenotes]
 deps =
-  -c{env:TOX_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2024.2}
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees --keep-going -b html releasenotes/source releasenotes/build/html