Make tox.ini tox 4.0 compatible

* use min version 4.2.5, for fixes [1][2][3]
* passenv fixed as space-separated list is not allowed anymore
* doc target uses requirements.txt as well as docs/requirements.txt
* skipsdist is not supported
* Add usedevelop = False so that aodh-api gets installed

Update setup.cfg: [files] -> [options]

[1] tox-dev/tox#2754
[2] tox-dev/tox#2824
[3] tox-dev/tox#2828

Change-Id: I2422dc17e6c73ef346de80e57cdf61ef5d271d69

setup.cfg

@@ -22,7 +22,7 @@ classifier =
     Programming Language :: Python :: 3.9
     Topic :: System :: Monitoring
 
-[files]
+[options]
 packages =
     aodh
 

tox.ini

@@ -1,12 +1,11 @@
 [tox]
-minversion = 3.18.0
-skipsdist = True
-envlist = py{3}{,-mysql,-postgresql},functional,pep8
+minversion = 4.2.5
+envlist = py3{,-mysql,-postgresql},functional,pep8
 ignore_basepython_conflict = True
 
 [testenv]
 basepython = python3
-usedevelop = True
+usedevelop = False
 setenv =
     OS_STDOUT_CAPTURE=1
     OS_STDERR_CAPTURE=1
@@ -22,11 +21,19 @@ setenv =
 deps =
     -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
     .[test,{env:AODH_TEST_DEPS}]
-passenv = OS_TEST_TIMEOUT OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_LOG_CAPTURE AODH_TEST_DRIVERS
+    -r{toxinidir}/requirements.txt
+passenv =
+    OS_TEST_TIMEOUT
+    OS_STDOUT_CAPTURE
+    OS_STDERR_CAPTURE
+    OS_LOG_CAPTURE
+    AODH_TEST_DRIVERS
 commands =
     {toxinidir}/run-tests.sh {posargs}
     aodh-config-generator
-allowlist_externals = bash
+allowlist_externals =
+    bash
+    {toxinidir}/run-tests.sh
 
 [testenv:cover]
 setenv =
@@ -53,18 +60,28 @@ deps = {[testenv:docs]deps}
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:docs]
+usedevelop = True
 deps =
   -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/requirements.txt
   -r{toxinidir}/doc/requirements.txt
-commands = sphinx-build -W -b html doc/source doc/build/html
+allowlist_externals =
+  rm
+commands =
+  rm -rf doc/build/html
+  sphinx-build -W --keep-going -b html doc/source doc/build/html
 setenv = PYTHONHASHSEED=0
 
 [testenv:pdf-docs]
+envdir = {toxworkdir}/docs
+usedevelop = {[testenv:docs]usedevelop}
 deps = {[testenv:docs]deps}
 allowlist_externals =
   make
+  rm
 commands =
-  sphinx-build -W -b latex doc/source doc/build/pdf
+  rm -rf  doc/build/pdf
+  sphinx-build -W --keep-going -b latex doc/source doc/build/pdf
   make -C doc/build/pdf
 
 [testenv:venv]