Drop lower-constraints

Per a general OpenStack resolution [1], lower-constraints
are not worth the extra work and confusion they introduce.
This patch drops them along with all mentions.

[1] http://lists.openstack.org/pipermail/openstack-discuss/2020-December/019521.html

Change-Id: Ib13e4f07aa6ee76be329d9eec9180c1fe31b9593

.zuul.yaml

@@ -60,7 +60,6 @@
       - ^\.mailmap$
       - ^\.zuul.yaml$
       - ^LICENSE$
-      - ^lower-constraints.txt$
       - \.rst$
     vars:
       test_matrix_configs: [neutron]
@@ -137,7 +136,6 @@
     templates:
       - check-requirements
       - openstack-cover-jobs
-      - openstack-lower-constraints-jobs
       - openstack-python3-wallaby-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3

lower-constraints.txt

@@ -1,112 +0,0 @@
-alabaster==0.7.10
-alembic==0.9.8
-amqp==2.2.2
-appdirs==1.4.3
-automaton==1.14.0
-Babel==2.3.4
-cachetools==2.0.1
-certifi==2018.1.18
-chardet==3.0.4
-cliff==2.11.0
-cmd2==0.8.1
-contextlib2==0.5.5
-coverage==4.0
-ddt==1.0.1
-debtcollector==1.19.0
-decorator==4.2.1
-doc8==0.6.0
-docutils==0.14
-dogpile.cache==0.6.5
-dulwich==0.19.0
-enum-compat==0.0.2
-eventlet==0.20.0
-extras==1.0.0
-fasteners==0.14.1
-fixtures==3.0.0
-futurist==1.6.0
-greenlet==0.4.13
-idna==2.6
-imagesize==1.0.0
-iso8601==0.1.11
-Jinja2==2.10
-jsonschema==3.2.0
-keystoneauth1==3.4.0
-keystonemiddleware==4.17.0
-kombu==4.6.1
-linecache2==1.0.0
-Mako==1.0.7
-MarkupSafe==1.1.1
-microversion-parse==0.2.1
-mox3==0.25.0
-msgpack==0.5.6
-netaddr==0.7.19
-netifaces==0.10.6
-networkx==1.11
-openstacksdk==0.35.0 # Apache-2.0
-os-client-config==1.29.0
-oslo.cache==1.29.0
-oslo.concurrency==3.26.0
-oslo.config==5.2.0
-oslo.context==2.19.2
-oslo.db==4.44.0
-oslo.i18n==3.15.3
-oslo.log==3.36.0
-oslo.messaging==5.29.0
-oslo.middleware==3.31.0
-oslo.policy==1.30.0
-oslo.serialization==2.25.0
-oslo.service==1.24.0
-oslo.upgradecheck==0.1.0
-oslo.utils==3.33.0
-oslo.versionedobjects==1.31.2
-oslosphinx==4.7.0
-oslotest==3.2.0
-Paste==2.0.3
-PasteDeploy==1.5.2
-pbr==2.0.0
-pika-pool==0.1.3
-pika==0.10.0
-prettytable==0.7.2
-psycopg2==2.8
-pycadf==2.7.0
-Pygments==2.2.0
-pyinotify==0.9.6
-PyMySQL==0.7.6
-pyparsing==2.2.0
-pyperclip==1.6.0
-python-dateutil==2.7.0
-python-editor==1.0.3
-python-keystoneclient==3.15.0
-python-mimeparse==1.6.0
-python-novaclient==9.1.0
-python-subunit==1.0.0
-pytz==2018.3
-PyYAML==3.13
-repoze.lru==0.7
-requests-mock==1.2.0
-requests==2.18.4
-requestsexceptions==1.4.0
-rfc3986==1.1.0
-Routes==2.4.1
-simplejson==3.13.2
-snowballstemmer==1.2.1
-sqlalchemy-migrate==0.11.0
-SQLAlchemy==1.2.19
-sqlparse==0.2.4
-statsd==3.2.2
-stestr==1.0.0
-stevedore==1.20.0
-SQLAlchemy-Utils==0.33.10
-taskflow==2.16.0
-Tempita==0.5.2
-tenacity==4.9.0
-testresources==2.0.0
-testscenarios==0.4
-testtools==2.2.0
-traceback2==1.4.0
-unittest2==1.1.0
-urllib3==1.22
-vine==1.1.4
-voluptuous==0.11.1
-WebOb==1.7.1
-wrapt==1.10.11

tox.ini

@@ -140,12 +140,6 @@ extension =
     M334 = checks:check_policy_enforce
 paths = ./masakari/hacking
 
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt
-
 [testenv:bindep]
 # Do not install any requirements. We want this to be fast and work even if
 # system dependencies are missing, since it's used to tell you what system