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: Iadebd5f857d446870fa79a96dab0ce8f111854f5

.zuul.yaml

@@ -4,5 +4,4 @@
       - check-requirements
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
-      - openstack-lower-constraints-jobs
       - openstack-cover-jobs

lower-constraints.txt

@@ -1,76 +0,0 @@
-anyjson==0.3.3
-appdirs==1.3.0
-asn1crypto==0.23.0
-Babel==2.3.4
-cffi==1.14.0
-cliff==2.8.0
-cmd2==0.8.0
-coverage==4.0
-cryptography==2.7
-debtcollector==1.2.0
-decorator==4.3.0
-deprecation==1.0
-dogpile.cache==0.6.2
-extras==1.0.0
-fixtures==3.0.0
-idna==2.6
-iso8601==0.1.11
-Jinja2==2.10
-jmespath==0.9.0
-jsonpatch==1.16
-jsonpointer==1.13
-jsonschema==2.6.0
-keystoneauth1==3.4.0
-linecache2==1.0.0
-MarkupSafe==1.1.1
-monotonic==0.6
-msgpack-python==0.5.6
-munch==2.1.0
-netaddr==0.7.18
-netifaces==0.10.4
-openstacksdk==0.11.2
-os-apply-config==5.0.0
-os-client-config==1.28.0
-os-service-types==1.2.0
-osc-lib==1.8.0
-oslo.config==5.2.0
-oslo.i18n==3.15.3
-oslo.serialization==2.18.0
-oslo.utils==3.33.0
-pbr==2.0.0
-positional==1.2.1
-prettytable==0.7.2
-pycparser==2.18
-pycrypto==2.6
-pyOpenSSL==17.1.0
-pyparsing==2.1.0
-pyperclip==1.5.27
-pystache==0.5.4
-python-cinderclient==3.3.0
-python-glanceclient==2.8.0
-python-heatclient==1.10.0
-python-keystoneclient==3.8.0
-python-mimeparse==1.6.0
-python-novaclient==9.1.0
-python-openstackclient==3.12.0
-python-subunit==1.0.0
-python-swiftclient==3.2.0
-pytz==2018.3
-PyYAML==3.13
-pyzmq==19.0.2
-requests==2.14.2
-requests-mock==1.1.0
-requestsexceptions==1.2.0
-rfc3986==0.3.1
-salt==3001.1
-simplejson==3.5.1
-six==1.10.0
-stevedore==1.20.0
-stestr==2.0.0
-testscenarios==0.4
-testtools==2.2.0
-tornado==4.4.3
-traceback2==1.4.0
-unittest2==1.1.0
-warlock==1.2.0
-wrapt==1.7.0

tox.ini

@@ -49,9 +49,3 @@ deps =
     -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
     -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt