Fix mypy precommit (#6110)

This seems to have conflicted between changing the types and updating the version in
pre-commit. Oddly, the code work when running `mypy` but not running in pre-commit.

But this code solves for both

.pre-commit-config.yaml

@@ -32,7 +32,7 @@ repos:
   #     - id: velin
   #       args: ["--write", "--compact"]
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v0.920
+    rev: v0.930
     hooks:
       - id: mypy
         # `properies` & `asv_bench` are copied from setup.cfg.

xarray/core/dataset.py

@@ -1068,12 +1068,12 @@ def persist(self, **kwargs) -> "Dataset":
     @classmethod
     def _construct_direct(
         cls,
-        variables: Mapping[Any, Variable],
+        variables: Dict[Any, Variable],
         coord_names: Set[Hashable],
-        dims: Mapping[Any, int] = None,
-        attrs: Mapping = None,
-        indexes: Mapping[Any, Index] = None,
-        encoding: Mapping = None,
+        dims: Dict[Any, int] = None,
+        attrs: Dict = None,
+        indexes: Dict[Any, Index] = None,
+        encoding: Dict = None,
         close: Callable[[], None] = None,
     ) -> "Dataset":
         """Shortcut around __init__ for internal use when we want to skip