Merge "tox: Remove ineffective ignore_basepython_conflict and bump minimum version"

tox.ini

@@ -1,12 +1,9 @@
 [tox]
-minversion = 4.0
+minversion = 4.6.0
 skipsdist = True
 envlist = docs,molecule
-ignore_basepython_conflict = True
-
 
 [testenv]
-basepython = python3
 usedevelop = False
 install_command =
     pip install -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
@@ -33,16 +30,15 @@ setenv =
     VIRTUAL_ENV={envdir}
     WORKING_DIR={toxinidir}
 
-
 [testenv:docs]
 deps =
-  -r{toxinidir}/doc/requirements.txt
+    -r{toxinidir}/doc/requirements.txt
+    -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
 commands =
     bash -c "rm -rf doc/build"
     doc8 doc
     sphinx-build -W -b html doc/source doc/build/html
 
-
 [testenv:pdf-docs]
 deps = {[testenv:docs]deps}
 allowlist_externals =
@@ -51,24 +47,20 @@ commands =
   sphinx-build -W -b latex doc/source doc/build/pdf
   make -C doc/build/pdf
 
-
 [doc8]
 # Settings for doc8:
 extensions = .rst
 
-
 [testenv:releasenotes]
 deps = {[testenv:docs]deps}
 commands =
     sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
-
 # environment used by the -infra templated docs job
 [testenv:venv]
 commands =
     {posargs}
 
-
 [testenv:molecule]
 # You can use DOCKER_REGISTRY and DOCKER_IMAGE_TAG to switch between
 # tested distros. I.e: