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: I6c0a5d5aa56f1341cba6d971a312fee57bb2cf8f

lower-constraints.txt

@@ -1,16 +0,0 @@
-coverage==4.0
-Flask==1.0.2
-ironic-lib==4.6.1
-itsdangerous==2.0.1
-Jinja2==2.11.3
-libvirt-python==6.0.0
-MarkupSafe==2.0.1
-munch==2.1.0
-openstacksdk==0.13.0
-oslotest==3.2.0
-pbr==2.0.0
-requests==2.14.2
-stestr==1.0.0
-tenacity==6.2.0
-testtools==2.2.0
-Werkzeug==2.0.3

requirements.txt

@@ -1,3 +1,7 @@
+# Requirements lower bounds listed here are our best effort to keep them up to
+# date but we do not test them so no guarantee of having them all correct. If
+# you find any incorrect lower bounds, let us know or propose a fix.
+
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.

tox.ini

@@ -66,9 +66,3 @@ exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 import-order-style = pep8
 application-import-names = sushy_tools
 filename = *.py
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt

zuul.d/project.yaml

@@ -1,7 +1,6 @@
 - project:
     templates:
       - check-requirements
-      - openstack-lower-constraints-master-branch-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
     check: