Fix false positive

Author: jonathandung

stdlib/_operator.pyi

@@ -264,7 +264,7 @@ def setitem(a: MutableMapping[_K, _V], b: _K, c: _V, /) -> None: ...
 def length_hint(obj: object, default: int = 0, /) -> int: ...
 def iadd(a: _SupportsIAdd[_T_contra, _T_co], b: _T_contra, /) -> _T_co: ...
 def iand(a: _SupportsIAnd[_T_contra, _T_co], b: _T_contra, /) -> _T_co: ...
-def iconcat(a: MutableSequence[_T], b: Sequence[_T], /) -> MutableSequence[_T]: ...
+def iconcat(a: MutableSequence[_T], b: Sequence[_T], /) -> MutableSequence[_T]: ... # currently impossible to type more precisely
 def ifloordiv(a: _SupportsIFloorDiv[_T_contra, _T_co], b: _T_contra, /) -> _T_co: ...
 def ilshift(a: _SupportsILShift[_T_contra, _T_co], b: _T_contra, /) -> _T_co: ...
 def imod(a: _SupportsIMod[_T_contra, _T_co], b: _T_contra, /) -> _T_co: ...
@@ -283,10 +283,7 @@ if sys.version_info >= (3, 11):
 if sys.version_info >= (3, 12):
     from collections.abc import Buffer
 
-    _B = TypeVar("_B", bound=Buffer)
-    @overload
-    def _compare_digest(a: str, b: str, /) -> bool: ...
-    @overload
+    _B = TypeVar("_B", str, Buffer)
     def _compare_digest(a: _B, b: _B, /) -> bool: ...
 
 else: