fix: ship py.typed so type checkers read the package's types

The package declares "Typing :: Typed" but shipped no PEP 561 marker, so
mypy in driver repositories treated it as untyped. Add the marker, include
it as package data, and release 4.7.1.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "napalm-device-types"
-version = "4.7.0"
+version = "4.7.1"
 description = "Abstract device-type base classes for NAPALM drivers"
 readme = "README.md"
 requires-python = ">=3.10"
@@ -61,6 +61,9 @@ dev = [
 where = ["."]
 include = ["napalm_device_types*"]
 
+[tool.setuptools.package-data]
+napalm_device_types = ["py.typed"]
+
 [tool.mypy]
 python_version = "3.10"
 strict = true