[portage] add __getaddr__ to root to mark incomplete

Author: Tatsh

stubs/portage/portage/__init__.pyi

@@ -13,3 +13,5 @@ class _DBRootDict(TypedDict):
 db: Mapping[str, _DBRootDict]
 root: str
 settings: config
+
+def __getattr__(name: str): ...  # incomplete module

stubs/portage/portage/dbapi/__init__.pyi

@@ -30,3 +30,5 @@ class dbapi:
         myrepo: str | None = ...,
     ) -> list[str]: ...
     def match(self, mydep: str, use_cache: Literal[0, 1] = ...) -> list[str] | str: ...
+
+def __getattr__(name: str): ...  # incomplete module