stdlib: fix many attributes which are read-only at runtime but read-write in the stub (#7395)

stdlib/importlib/machinery.pyi

@@ -22,7 +22,8 @@ class ModuleSpec:
     submodule_search_locations: list[str] | None
     loader_state: Any
     cached: str | None
-    parent: str | None
+    @property
+    def parent(self) -> str | None: ...
     has_location: bool
     def __eq__(self, other: object) -> bool: ...
 

stdlib/importlib/metadata/__init__.pyi

@@ -42,7 +42,9 @@ if sys.version_info >= (3, 10):
     from importlib.metadata._meta import PackageMetadata as PackageMetadata
     def packages_distributions() -> Mapping[str, list[str]]: ...
 
-class PackageNotFoundError(ModuleNotFoundError): ...
+class PackageNotFoundError(ModuleNotFoundError):
+    @property
+    def name(self) -> str: ...  # type: ignore[override]
 
 class _EntryPointBase(NamedTuple):
     name: str