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: I011e9d6e0787dae20607040bc08e7335ff306862

.zuul.yaml

@@ -2,7 +2,6 @@
     templates:
       - check-requirements
       - openstack-cover-jobs
-      - openstack-lower-constraints-jobs
       - openstack-python3-zed-jobs
     check:
       jobs:

lower-constraints.txt

@@ -1,55 +0,0 @@
-appdirs==1.3.0
-Babel==2.3.4
-bandit==1.4.0
-confluent-kafka==1.3.0
-coverage==4.0
-debtcollector==1.2.0
-docutils==0.14
-extras==1.0.0
-fixtures==3.0.0
-future==0.16.0
-gevent==1.2.2
-gitdb==0.6.4
-GitPython==1.0.1
-greenlet==0.4.15
-httplib2==0.9.1
-iso8601==0.1.11
-kazoo==2.8.0
-keystoneauth1==3.4.0
-linecache2==1.0.0
-monotonic==0.6
-mox3==0.20.0
-msgpack-python==0.4.0
-netaddr==0.7.20
-netifaces==0.10.4
-os-client-config==1.28.0
-os-testr==1.0.0
-oslo.config==6.8.0
-oslo.context==2.22.0
-oslo.i18n==3.15.3
-oslo.policy==3.6.0
-oslo.serialization==2.18.0
-oslo.utils==4.5.0
-oslotest==3.2.0
-pbr==2.0.0
-PyMySQL==0.8.0
-pyparsing==2.1.0
-python-mimeparse==1.6.0
-python-subunit==1.0.0
-pytz==2013.6
-PyYAML==5.1
-requests==2.20.0
-requests-mock==1.2.0
-requestsexceptions==1.2.0
-rfc3986==1.2.0
-simplejson==3.13.2
-smmap==0.9.0
-stestr==1.0.0
-stevedore==1.20.0
-tabulate==0.8.1
-testrepository==0.0.18
-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

@@ -90,11 +90,3 @@ show-source = True
 # In addition ignore for now:
 # W504 line break after binary operator
 ignore = H101,H301,H404,H405,W504
-
-[testenv:lower-constraints]
-setenv = {[testenv:py36]setenv}
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt
-commands = {[testenv:py36]commands}