Add pyproject.toml to support pip 23.1

pip 23.1 removed the "setup.py install" fallback for projects that do
not have pyproject.toml and now uses a pyproject.toml which is vendored
in pip [1][2]. pip 24.2 has now deprecated a similar fallback to
"setup.py develop" and plans to fully remove this in pip 25.0 [3][4][5].
pbr supports editable installs since 6.0.0 so we can get ahead of this
by adding our own minimal pyproject.toml to ensure we are using the
correct build system.

[1] https://pip.pypa.io/en/stable/news/#v23-1
[2] https://github.com/pypa/pip/issues/8368
[3] https://pip.pypa.io/en/stable/news/#v24-2
[4] https://github.com/pypa/pip/issues/11457
[5] https://ichard26.github.io/blog/2024/08/whats-new-in-pip-24.2/

Change-Id: I3407c8aa26d4ee96747cbca45e85894f193fc625
Co-Authored-By: Sean Mooney <work@seanmooney.info>
Signed-off-by: Ivan Anfimov <lazekteam@gmail.com>

pyproject.toml

@@ -0,0 +1,3 @@
+[build-system]
+requires = ["pbr>=6.0.0", "setuptools<82.0.0"]
+build-backend = "pbr.build"

requirements.txt

@@ -2,8 +2,7 @@
 # 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.
 
-alabaster<0.7.14
-pbr>=2.0.0 # Apache-2.0
+alabaster<0.7.14 # BSD
 Babel>=2.3.4 # BSD
 itsdangerous<2.1 # BSD
 Flask!=0.11,<1.0,>=0.10 # BSD
@@ -17,11 +16,11 @@ oslo.serialization>=1.10.0 # Apache-2.0
 oslo.utils>=3.20.0 # Apache-2.0
 paramiko>=2.0 # LGPLv2.1+
 psutil>=3.2.2 # BSD
-PyGithub
+PyGithub # LGPL
 python-memcached>=1.56 # PSF
 PyYAML>=3.10.0 # MIT
 requests!=2.12.2,!=2.13.0,>=2.10.0 # Apache-2.0
-requests-file
-sh
+requests-file # Apache-2.0
+sh # MIT
 six>=1.9.0 # MIT
-setuptools<82.0.0
+setuptools<82.0.0 # MIT

setup.py

@@ -15,6 +15,4 @@
 
 import setuptools
 
-setuptools.setup(
-    setup_requires=['pbr>=2.0.0'],
-    pbr=True)
+setuptools.setup(pbr=True)

test-requirements.txt

@@ -7,6 +7,6 @@ python-subunit>=0.0.18 # Apache-2.0/BSD
 sphinx>=1.5.1,<2.0.0 # BSD
 sphinxcontrib-httpdomain # BSD
 stestr>=2.0.0 # Apache-2.0
-testtools>=1.4.0 # MIT
-setuptools<82.0.0
-jinja2<3.1.0
+testtools>=2.2.0 # MIT
+setuptools<82.0.0 # MIT
+jinja2<3.1.0 # BSD