Just use poetry-core and remove directives that are unknown for it.

Avoid the installation of the test suite into the top of Python's site-lib.

--- pyproject.toml.orig	2023-10-29 15:08:28 UTC
+++ pyproject.toml
@@ -2,9 +2,8 @@
 
 [build-system]
 # See -> PEP 517
-requires = ["poetry>=1.5.1", "poetry-core>=1.6.1", "wheel>=0.38.4", "packaging>=23.0"]
+requires = ["poetry-core>=1.6.1", "wheel>=0.38.4", "packaging>=23.0"]
 build-backend = "poetry.core.masonry.api"
-requires-python = ">=3.8.0"
 
 ##############################################################################
 #
@@ -38,7 +37,6 @@ packages = [
 packages = [
     # Syntax -> https://python-poetry.org/docs/pyproject/#packages
     { include = "ciscoconfparse/*" },
-    { include = "tests/*" },
 ]
 # See -> https://python-poetry.org/docs/pyproject/#include-and-exclude
 include = [