Fix mypy failure on CI (#7198)

distributed/shuffle/shuffle.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Any
 
 from dask.base import tokenize
 from dask.highlevelgraph import HighLevelGraph
@@ -91,15 +91,15 @@ def rearrange_by_column_p2p(
 class P2PShuffleLayer(SimpleShuffleLayer):
     def __init__(
         self,
-        name,
-        column,
-        npartitions,
-        npartitions_input,
-        ignore_index,
-        name_input,
-        meta_input,
-        parts_out=None,
-        annotations=None,
+        name: str,
+        column: str,
+        npartitions: int,
+        npartitions_input: int,
+        ignore_index: bool,
+        name_input: str,
+        meta_input: pd.DataFrame,
+        parts_out: list | None = None,
+        annotations: dict | None = None,
     ):
         annotations = annotations or {}
         annotations.update({"shuffle": lambda key: key[1]})
@@ -115,16 +115,16 @@ def __init__(
             annotations=annotations,
         )
 
-    def get_split_keys(self):
+    def get_split_keys(self) -> list:
         # TODO: This is doing some funky stuff to set priorities but we don't need this
         return []
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return (
             f"{type(self).__name__}<name='{self.name}', npartitions={self.npartitions}>"
         )
 
-    def _cull(self, parts_out):
+    def _cull(self, parts_out: list) -> P2PShuffleLayer:
         return P2PShuffleLayer(
             self.name,
             self.column,
@@ -136,9 +136,9 @@ def _cull(self, parts_out):
             parts_out=parts_out,
         )
 
-    def _construct_graph(self, deserializing=None):
+    def _construct_graph(self, deserializing: Any = None) -> dict[tuple | str, tuple]:
         token = tokenize(self.name_input, self.column, self.npartitions, self.parts_out)
-        dsk = {}
+        dsk: dict[tuple | str, tuple] = {}
         barrier_key = "shuffle-barrier-" + token
         name = "shuffle-transfer-" + token
         tranfer_keys = list()