[ignore][codex-test] Add typing to simple library registry (#161367)

## Summary
- add type annotations for simple library registry and dispatch rule holder
- remove allow-untyped-defs directive

## Testing
- `python -m mypy torch/_library/simple_registry.py` *(fails: repo expects mypy==1.16.0)*
- `lintrunner -a torch/_library/simple_registry.py` *(fails: attr-defined error in torchgen/gen_schema_utils.py)*
- `python test/test_torch.py TestTorch.test_dir` *(fails: ModuleNotFoundError: No module named 'torch')*

------
https://chatgpt.com/codex/tasks/task_e_68aa3cc210488326befdd992c79115a0
Pull Request resolved: https://github.com/pytorch/pytorch/pull/161367
Approved by: https://github.com/Skylion007

torch/_library/simple_registry.py

@@ -1,5 +1,4 @@
-# mypy: allow-untyped-defs
-from typing import Callable, Optional
+from typing import Any, Callable, Optional
 
 from .fake_impl import FakeImplHolder
 from .utils import RegistrationHandle
@@ -24,8 +23,8 @@ class SimpleLibraryRegistry:
     (including the overload) to SimpleOperatorEntry.
     """
 
-    def __init__(self):
-        self._data = {}
+    def __init__(self) -> None:
+        self._data: dict[str, SimpleOperatorEntry] = {}
 
     def find(self, qualname: str) -> "SimpleOperatorEntry":
         res = self._data.get(qualname, None)
@@ -44,7 +43,7 @@ class SimpleOperatorEntry:
     registered to.
     """
 
-    def __init__(self, qualname: str):
+    def __init__(self, qualname: str) -> None:
         self.qualname: str = qualname
         self.fake_impl: FakeImplHolder = FakeImplHolder(qualname)
         self.torch_dispatch_rules: GenericTorchDispatchRuleHolder = (
@@ -53,17 +52,17 @@ class SimpleOperatorEntry:
 
     # For compatibility reasons. We can delete this soon.
     @property
-    def abstract_impl(self):
+    def abstract_impl(self) -> FakeImplHolder:
         return self.fake_impl
 
 
 class GenericTorchDispatchRuleHolder:
-    def __init__(self, qualname):
-        self._data = {}
-        self.qualname = qualname
+    def __init__(self, qualname: str) -> None:
+        self._data: dict[type, Callable[..., Any]] = {}
+        self.qualname: str = qualname
 
     def register(
-        self, torch_dispatch_class: type, func: Callable
+        self, torch_dispatch_class: type, func: Callable[..., Any]
     ) -> RegistrationHandle:
         if self.find(torch_dispatch_class):
             raise RuntimeError(
@@ -71,16 +70,18 @@ class GenericTorchDispatchRuleHolder:
             )
         self._data[torch_dispatch_class] = func
 
-        def deregister():
+        def deregister() -> None:
             del self._data[torch_dispatch_class]
 
         return RegistrationHandle(deregister)
 
-    def find(self, torch_dispatch_class):
+    def find(self, torch_dispatch_class: type) -> Optional[Callable[..., Any]]:
         return self._data.get(torch_dispatch_class, None)
 
 
-def find_torch_dispatch_rule(op, torch_dispatch_class: type) -> Optional[Callable]:
+def find_torch_dispatch_rule(
+    op: Any, torch_dispatch_class: type
+) -> Optional[Callable[..., Any]]:
     return singleton.find(op.__qualname__).torch_dispatch_rules.find(
         torch_dispatch_class
     )