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: Ie57cd00b241d810528d51c5afbef604db841b0ce

lower-constraints.txt

@@ -1,48 +0,0 @@
-alabaster==0.7.10
-appdirs==1.4.3
-astroid==2.4.0
-Babel==2.3.4
-cliff==2.8.0
-cmd2==0.8.0
-coverage==4.0
-docutils==0.11
-dulwich==0.15.0
-extras==1.0.0
-fixtures==3.0.0
-flake8==3.7.9
-future==0.16.0
-hacking==3.0.1
-imagesize==0.7.1
-iso8601==0.1.11
-isort==4.3.21
-Jinja2==2.10
-keystoneauth1==3.4.0
-linecache2==1.0.0
-logilab-common==1.4.1
-MarkupSafe==1.0
-mccabe==0.6.1
-mox3==0.20.0
-netaddr==0.7.18
-os-client-config==1.28.0
-oslo.utils==3.33.0
-oslotest==3.2.0
-ovs==2.10.0
-pbr==2.0.0
-pep8==1.5.7
-pyflakes==2.1.1
-Pygments==2.2.0
-pylint==2.6.0
-python-mimeparse==1.6.0
-python-subunit==1.0.0
-pytz==2013.6
-PyYAML==5.3.1
-requests==2.14.2
-requestsexceptions==1.2.0
-six==1.12.0
-snowballstemmer==1.2.1
-stevedore==1.20.0
-stestr==2.0.0
-testscenarios==0.4
-testtools==2.2.0
-traceback2==1.4.0
-unittest2==1.1.0

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

@@ -85,9 +85,3 @@ enable-extensions=H106,H203,H204,H205,H904
 show-source = True
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 import-order-style = pep8
-
-[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-jobs
       - openstack-python3-yoga-jobs
       - publish-openstack-docs-pti
     check: