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: Ifb9dc54424256d5cffe557894b2d26b2401ebf92

.zuul.yaml

@@ -6,7 +6,3 @@
       - check-requirements
       - lib-forward-testing-python3
       - release-notes-jobs-python3
-    check:
-      jobs:
-        - openstack-tox-lower-constraints:
-            voting: false

lower-constraints.txt

@@ -1,84 +0,0 @@
-appdirs==1.4.3
-asn1crypto==0.24.0
-Babel==2.5.3
-bandit==1.1.0
-beautifulsoup4==4.6.0
-certifi==2018.1.18
-cffi==1.14.0
-chardet==3.0.4
-cliff==2.11.0
-cmd2==0.8.1
-coverage==4.0
-cryptography==3.0
-debtcollector==1.19.0
-dogpile.cache==0.6.5
-dulwich==0.19.0
-extras==1.0.0
-fixtures==3.0.0
-flake8-docstrings==0.2.1.post1
-flake8==2.2.4
-future==0.16.0
-gitdb2==2.0.3
-GitPython==2.1.8
-hacking==0.10.0
-idna==2.6
-iso8601==0.1.12
-keystoneauth1==3.12.0
-linecache2==1.0.0
-mccabe==0.2.1
-mock==2.0.0
-monotonic==1.4
-mox3==0.25.0
-msgpack==0.5.6
-netaddr==0.7.19
-netifaces==0.10.6
-openstack-requirements==1.2.0
-os-client-config==1.29.0
-os-testr==1.0.0
-oslo.cache==1.26.0
-oslo.config==5.2.0
-oslo.context==2.19.2
-oslo.i18n==3.15.3
-oslo.log==3.36.0
-oslo.messaging==5.29.0
-oslo.serialization==2.18.0
-oslo.utils==3.33.0
-oslotest==3.2.0
-packaging==17.1
-Parsley==1.3
-pbr==2.0.0
-pep257==0.7.0
-pep8==1.5.7
-prettytable==0.7.2
-pycadf==1.1.0
-pycparser==2.18
-pyflakes==0.8.1
-pyinotify==0.9.6
-pyparsing==2.2.0
-pyperclip==1.6.0
-python-dateutil==2.7.0
-python-keystoneclient==3.20.0
-python-memcached==1.59
-python-mimeparse==1.6.0
-python-subunit==1.2.0
-pytz==2018.3
-PyYAML==3.13
-requests-mock==1.2.0
-requests==2.14.2
-requestsexceptions==1.4.0
-rfc3986==1.1.0
-six==1.10.0
-smmap2==2.0.3
-stestr==2.0.0
-stevedore==1.20.0
-testrepository==0.0.18
-testresources==2.0.0
-testtools==2.2.0
-traceback2==1.4.0
-unittest2==1.1.0
-urllib3==1.22
-voluptuous==0.11.1
-waitress==1.1.0
-WebOb==1.7.1
-WebTest==2.0.27
-wrapt==1.10.11

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 @@ import_exceptions =
 extensions = .rst, .yaml
 # lines should not be longer than 79 characters.
 max-line-length = 79
-
-[testenv:lower-constraints]
-deps =
-  -c{toxinidir}/lower-constraints.txt
-  -r{toxinidir}/test-requirements.txt
-  -r{toxinidir}/requirements.txt