Drop lower-constraints.txt and its testingstable/ussuri

As discussed in TC PTG[1] and TC resolution[2], we are
dropping the lower-constraints.txt file and its testing.
We will keep lower bounds in the requirements.txt file but
with a note that these are not tested lower bounds and we
try our best to keep them updated.

[1] https://etherpad.opendev.org/p/tc-zed-ptg#L326
[2] https://governance.openstack.org/tc/resolutions/20220414-drop-lower-constraints.html#proposal

(cherry picked from commit 0475709c0734d8314637298de2fd2b005ad5a1cb)

Change-Id: Ia3f66b6805704c254295fd663f0260d5d963ed66

1 files changed, 1 insertions, 1 deletions

diff --git a/setup.py b/setup.py
index 566d844..74c3ac9 100644
--- a/setup.py
+++ b/setup.py
@@ -25,5 +25,5 @@ except ImportError:
     pass
 
 setuptools.setup(
-    setup_requires=['pbr>=2.0.0'],
+    setup_requires=['pbr>=5.9.0'],
     pbr=True)