fix: add black so our AI dev platform formats correctly

Author: astuyve

pyproject.toml

@@ -36,6 +36,7 @@ requests = { version ="^2.22.0", optional = true }
 pytest = { version= "^8.0.0", optional = true }
 pytest-benchmark = { version = "^4.0", optional = true }
 flake8 = { version = "^5.0.4", optional = true }
+black = { version = "==25.11.0", optional = true }
 
 [tool.poetry.extras]
 dev = [
@@ -44,8 +45,12 @@ dev = [
     "pytest",
     "pytest-benchmark",
     "requests",
+    "black",
 ]
 
+[tool.black]
+include = "(^datadog_lambda/.*\\.pyi?$|^tests/.*\\.pyi?$)"
+
 [build-system]
 requires = ["poetry-core>=1.0.0"]
 build-backend = "poetry.core.masonry.api"