Switch to poetry_core

Author: Mause

pyproject.toml

@@ -30,5 +30,5 @@ addopts = "--hypothesis-show-statistics"
 ignore_missing_imports = true
 
 [build-system]
-requires = ["poetry>=0.12"]
-build-backend = "poetry.masonry.api"
+requires = ["poetry_core>=1.0.0"]
+build-backend = "poetry.core.masonry.api"