Merge "Use pbr"

Author: Zuul

pyproject.toml

@@ -1,6 +1,6 @@
 [build-system]
-requires = ['setuptools>=68']
-build-backend = 'setuptools.build_meta'
+requires = ["pbr>=6.1.1"]
+build-backend = "pbr.build"
 
 [project]
 name = "python-observabilityclient"