Remove setup.py and setup.cfg

Theses used to be used for building docs in the past.

A recent release of setuptools 61.0.0 introduced a breaking change [1]
which caused our openstack-tox-docs and openstack-tox-pep8 jobs to fail
with:

  error: Multiple top-level packages discovered in a flat-layout:
    ['specs', 'priorities'].

This removes setup.py and setup.cfg from use in tox.ini to resolve the
issue and they are not needed anyway.

Related-Bug: #1966382
Change-Id: Ia653b3e13302db5bf2adc006aea5436a9c65616e

setup.cfg

@@ -1,12 +0,0 @@
-[metadata]
-name = glance-specs
-summary = OpenStack Glance Project Development Specs
-description-file =
-    README.rst
-author = OpenStack
-author-email = openstack-discuss@lists.openstack.org
-home-page = http://specs.openstack.org/openstack/glance-specs/
-classifier =
-    Intended Audience :: Developers
-    License :: OSI Approved :: Apache Software License
-    Operating System :: POSIX :: Linux

setup.py

@@ -1,22 +0,0 @@
-#!/usr/bin/env python
-# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#    http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
-# implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
-import setuptools
-
-setuptools.setup(
-    setup_requires=['pbr'],
-    pbr=True)

tox.ini

@@ -6,7 +6,6 @@ ignore_basepython_conflict = True
 
 [testenv]
 basepython = python3
-usedevelop = True
 setenv = VIRTUAL_ENV={envdir}
 deps = -r{toxinidir}/requirements.txt
 commands = stestr run --slowest {posargs}