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: I4c4ec3ef3f6016206cab1ae697985eaef8e95293

.zuul.yaml

@@ -1,7 +1,6 @@
 - project:
     templates:
       - openstack-cover-jobs
-      - openstack-lower-constraints-jobs
       - openstack-python3-zed-jobs
       - publish-openstack-docs-pti
       - check-requirements

lower-constraints.txt

@@ -1,72 +0,0 @@
-alabaster==0.7.10
-appdirs==1.3.0
-Babel==2.3.4
-bandit==1.4.0
-chardet==3.0.4
-cliff==2.8.0
-cmd2==0.8.0
-coverage==4.0
-debtcollector==1.2.0
-decorator==4.1.0
-deprecation==1.0
-doc8==0.8.1
-docutils==0.12
-dogpile.cache==0.6.2
-dulwich==0.15.0
-extras==1.0.0
-fixtures==3.0.0
-future==0.16.0
-gitdb==0.6.4
-GitPython==1.0.1
-imagesize==0.7.1
-iso8601==0.1.11
-Jinja2==2.10
-jmespath==0.9.0
-jsonpatch==1.16
-jsonpointer==1.13
-keystoneauth1==3.4.0
-linecache2==1.0.0
-MarkupSafe==1.0
-mccabe==0.6.0
-monotonic==0.6
-mox3==0.20.0
-msgpack-python==0.4.0
-munch==2.1.0
-netaddr==0.7.18
-netifaces==0.10.4
-openstackdocstheme==2.2.1
-openstacksdk==0.11.2
-os-client-config==1.28.0
-os-service-types==1.2.0
-os-testr==1.0.0
-osc-lib==1.8.0
-oslo.i18n==3.15.3
-oslo.serialization==2.18.0
-oslo.utils==3.33.0
-oslotest==3.2.0
-pbr==2.0.0
-prettytable==0.7.2
-pyflakes==2.1.0
-Pygments==2.2.0
-pyparsing==2.1.0
-pyperclip==1.5.27
-python-mimeparse==1.6.0
-python-subunit==1.0.0
-pytz==2013.6
-PyYAML==3.12
-reno==3.1.0
-requests==2.14.2
-requestsexceptions==1.2.0
-restructuredtext-lint==1.1.1
-simplejson==3.5.1
-smmap==0.9.0
-snowballstemmer==1.2.1
-Sphinx==2.0.0
-sphinxcontrib-websupport==1.0.1
-stestr==1.0.0
-stevedore==1.20.0
-testscenarios==0.4
-testtools==2.2.0
-traceback2==1.4.0
-unittest2==1.1.0
-wrapt==1.7.0

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

@@ -97,9 +97,3 @@ show-source = True
 max-line-length = 100
 builtins = _
 exclude=.venv,.git,.tox,dist,client_api_example.py,*lib/python*,*egg,build
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt