tox: Assorted changes

- Remove the 'linters' testenv: this battle has been lost
- Don't install package for the 'pep8' testenv: it's unnecessary
- Remove 'safety' from 'pep8' testenv: the command we were using is
  deprecated and the new one requires authentication
- Fix the 'bindep' testenv so it (once again) skips install of the
  package and do the same for the 'pep8' and 'babel' testenvs
- Stop setting 'basepython': everything is Python 3 nowadays (tox 4
  *only* supports that)
- Remove a linter from the 'test-requirements.txt' file: these
  dependencies are managed by tox
- Fix some indentation

Change-Id: I4805d1ac0fa0209c59f3815352ff9ea54108eca2
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

Author: stephenfin

test-requirements.txt

@@ -4,4 +4,3 @@ stestr>=1.0.0  # Apache-2.0
 testscenarios>=0.4 # Apache-2.0/BSD
 testtools>=2.2.0 # MIT
 virtualenv>=14.0.6 # MIT
-bashate>=0.5.1 # Apache-2.0

tox.ini

@@ -1,14 +1,13 @@
 [tox]
 minversion = 4.11.0
 envlist = validate,py3,pep8,pip-install
-ignore_basepython_conflict=true
 
 [testenv]
-basepython = python3
-usedevelop = True
-deps = -c{toxinidir}/upper-constraints.txt
-       -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
+usedevelop = true
+deps =
+  -c{toxinidir}/upper-constraints.txt
+  -r{toxinidir}/requirements.txt
+  -r{toxinidir}/test-requirements.txt
 commands =
   stestr run {posargs}
 
@@ -40,72 +39,56 @@ allowlist_externals =
   generate-constraints
 description = Regenerates upper-constraints.txt
 # Generate needs an unconstrained install to get new dependencies
-deps = -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
+deps =
+  -r{toxinidir}/requirements.txt
+  -r{toxinidir}/test-requirements.txt
 commands = generate-constraints {posargs: -d denylist.txt -r global-requirements.txt -p python3.9 -p python3.10 -p python3.11 -p python3.12 -p python3.13 > upper-constraints.txt}
 
 [testenv:validate]
 allowlist_externals =
   validate-constraints
 commands =
-    validate-constraints {toxinidir}/global-requirements.txt {toxinidir}/upper-constraints.txt {toxinidir}/denylist.txt
+  validate-constraints {toxinidir}/global-requirements.txt {toxinidir}/upper-constraints.txt {toxinidir}/denylist.txt
 
 [testenv:validate-projects]
 allowlist_externals =
   validate-projects
 commands = validate-projects {toxinidir}/projects.txt
 
-# TODO remove once zuul reconfigured to run linters on gate
 [testenv:pep8]
-deps = {[testenv:linters]deps}
-allowlist_externals =
-  bash
-commands =
-    flake8
-    bash -c "find {toxinidir}/tools      \
-                 -type f                 \
-                 -name \*.sh             \
-                 -print0 | xargs -0 bashate -v -iE006,E010"
-    bash -c 'sed -e "s,===,==," upper-constraints.txt > {envtmpdir}/safety-check.txt'
-    -safety check --json -r {envtmpdir}/safety-check.txt
-
-[testenv:linters]
 description = Perform linting
+skip_install = true
 deps =
-    hacking>=1.0.0
-    bashate>=0.5.1
-    safety
+  hacking~=7.0  # Apache-2.0
+  bashate~=2.1  # Apache-2.0
 allowlist_externals =
   bash
 commands =
-    flake8
-    bash -c "find {toxinidir}/tools      \
-                 -type f                 \
-                 -name \*.sh             \
-                 -print0 | xargs -0 bashate -v -iE006,E010"
-    bash -c 'sed -e "s,===,==," upper-constraints.txt > {envtmpdir}/safety-check.txt'
-    -safety check --json -r {envtmpdir}/safety-check.txt
+  flake8
+  bash -c "find {toxinidir}/tools      \
+               -type f                 \
+               -name \*.sh             \
+               -print0 | xargs -0 bashate -v -iE006,E010"
 
 [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
-# dependencies are missing! This also means that bindep must be installed
-# separately, outside of the requirements files, and develop mode disabled
-# explicitly to avoid unnecessarily installing the checked-out repo too (this
-# further relies on "tox.skipsdist = True" above).
+# dependencies are missing!
+skip_install = true
 deps = bindep
 commands = bindep test
 usedevelop = False
 
 [testenv:docs]
 allowlist_externals =
   sphinx-build
-deps = -c{env:TOX_CONSTRAINTS_FILE:{toxinidir}/upper-constraints.txt}
-       -r{toxinidir}/doc/requirements.txt
+deps =
+  -c{env:TOX_CONSTRAINTS_FILE:{toxinidir}/upper-constraints.txt}
+  -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:pip-install]
-recreate = True
+recreate = true
 deps = .
 commands = python {toxinidir}/tools/check-install.py
 
@@ -117,6 +100,7 @@ commands =
   {toxinidir}/playbooks/files/project-requirements-change.py --local {posargs}
 
 [testenv:babel]
+skip_install = true
 # Use the local upper-constraints.txt file
 allowlist_externals =
   {toxinidir}/tools/babel-test.sh