Use upper constraints from stackhpc/requirements

This is to fix the following issue:

    ModuleNotFoundError: No module named 'pkg_resources'

Change-Id: I96544c3f93a10b4e1a96dafd94ad0571ba28246f

Author: priteau

tox.ini

@@ -13,7 +13,7 @@ setenv = VIRTUAL_ENV={envdir}
          LC_ALL=en_US.UTF-8
          TESTS_DIR=./networking_generic_switch/tests/unit/
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
+    -c{env:TOX_CONSTRAINTS_FILE:https://raw.githubusercontent.com/stackhpc/requirements/refs/heads/stackhpc/2025.1/upper-constraints.txt}
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/test-requirements.txt
 passenv =
@@ -29,7 +29,7 @@ commands =
 
 [testenv:pep8]
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
+    -c{env:TOX_CONSTRAINTS_FILE:https://raw.githubusercontent.com/stackhpc/requirements/refs/heads/stackhpc/2025.1/upper-constraints.txt}
     hacking~=6.1.0 # Apache-2.0
     flake8-import-order~=0.18.0# LGPLv3
     bashate~=2.1.0 # Apache-2.0
@@ -48,7 +48,7 @@ commands =
 setenv = PYTHONHASHSEED=0
 sitepackages = False
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
+    -c{env:TOX_CONSTRAINTS_FILE:https://raw.githubusercontent.com/stackhpc/requirements/refs/heads/stackhpc/2025.1/upper-constraints.txt}
     -r{toxinidir}/requirements.txt
     -r{toxinidir}/doc/requirements.txt
 commands =
@@ -65,15 +65,15 @@ commands =
 
 [testenv:releasenotes]
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
+    -c{env:TOX_CONSTRAINTS_FILE:https://raw.githubusercontent.com/stackhpc/requirements/refs/heads/stackhpc/2025.1/upper-constraints.txt}
     -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:venv]
 setenv = PYTHONHASHSEED=0
 deps =
-    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/2025.1}
+    -c{env:TOX_CONSTRAINTS_FILE:https://raw.githubusercontent.com/stackhpc/requirements/refs/heads/stackhpc/2025.1/upper-constraints.txt}
     -r{toxinidir}/test-requirements.txt
     -r{toxinidir}/doc/requirements.txt
 commands = {posargs}