Drop lower-constraints.txt and its testing

As discussed in TC PTG[1] and TC resolution[2], we are
dropping the lower-constraints.txt file and its testing.
We will keep lower bounds in the requirements.txt file but
with a note that these are not tested lower bounds and we
try our best to keep them updated.

[1] https://etherpad.opendev.org/p/tc-zed-ptg#L326
[2] https://governance.openstack.org/tc/resolutions/20220414-drop-lower-constraints.html#proposal

Change-Id: I16ea0a61c018d03d6c23e0b0736295a36b6dd367

lower-constraints.txt

@@ -1,28 +0,0 @@
-Pint==0.5
-Werkzeug==2.0.0
-bandit==1.1.0
-coverage==4.0
-cryptography==2.3
-dogpile.cache==0.9.2
-eventlet==0.18.2
-importlib_metadata==1.7.0;python_version<'3.8'
-ironic-lib==5.1.0
-kazoo==2.8.0
-netifaces==0.10.4
-openstacksdk==0.49.0
-oslo.concurrency==3.26.0
-oslo.config==5.2.0
-oslo.log==3.36.0
-oslo.serialization==2.18.0
-oslo.service==1.24.0
-oslo.utils==3.34.0
-oslotest==3.2.0
-pbr==2.0.0
-psutil==3.2.2
-pyudev==0.18
-requests==2.14.2
-stestr==1.0.0
-stevedore==1.20.0
-tenacity==6.2.0
-testtools==2.2.0
-tooz==2.7.2

tox.ini

@@ -137,9 +137,3 @@ commands =
   pip install -e {toxinidir}/examples/business-logic
   pip install -e {toxinidir}/examples/vendor-device
   python -c 'import example_business_logic; import example_device'
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt

zuul.d/project.yaml

@@ -2,7 +2,6 @@
     templates:
       - check-requirements
       - openstack-cover-jobs
-      - openstack-lower-constraints-master-branch-jobs
       - openstack-python3-zed-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3