fix: missing c extensions with newer poetry

fix for breaking change in poetry python-poetry/poetry-core#318

pyproject.toml

@@ -13,11 +13,14 @@ classifiers = [
     "Operating System :: OS Independent",
     "Topic :: Software Development :: Libraries",
 ]
-build = "build_ext.py"
 packages = [
     { include = "home_assistant_bluetooth", from = "src" },
 ]
 
+[tool.poetry.build]
+generate-setup-file = true
+script = "build_ext.py"
+
 [tool.poetry.urls]
 "Bug Tracker" = "https://github.com/home-assistant-libs/home-assistant-bluetooth/issues"
 "Changelog" = "https://github.com/home-assistant-libs/home-assistant-bluetooth/blob/main/CHANGELOG.md"