Fix mypy issues from better pymbolic/pytools typing

.pylintrc-local.yml

@@ -3,3 +3,6 @@
 
 - arg: extension-pkg-whitelist
   val: mayavi
+- arg: ignored-modules
+  val:
+  - symengine

sumpy/expansion/__init__.py

@@ -283,7 +283,7 @@ def get_stored_mpole_coefficients_from_full(self,
     # }}}
 
     @memoize_method
-    def get_full_coefficient_identifiers(self) -> list[Hashable]:
+    def get_full_coefficient_identifiers(self) -> Sequence[Hashable]:
         """
         Returns identifiers for every coefficient in the complete expansion.
         """

sumpy/kernel.py

@@ -31,7 +31,8 @@
 import sympy as sp
 
 import loopy as lp
-from pymbolic import var
+import pymbolic.primitives as prim
+from pymbolic import Expression, var
 from pymbolic.mapper import CSECachingMapperMixin, IdentityMapper
 from pymbolic.primitives import make_sym_vector
 from pytools import memoize_method
@@ -1084,7 +1085,7 @@ def replace_inner_kernel(self, new_inner_kernel):
     mapper_method = "map_axis_target_derivative"
 
 
-class _VectorIndexAdder(CSECachingMapperMixin, IdentityMapper):
+class _VectorIndexAdder(CSECachingMapperMixin[Expression, []], IdentityMapper[[]]):
     def __init__(self, vec_name, additional_indices):
         self.vec_name = vec_name
         self.additional_indices = additional_indices
@@ -1099,7 +1100,14 @@ def map_subscript(self, expr):
         else:
             return IdentityMapper.map_subscript(self, expr)
 
-    map_common_subexpression_uncached = IdentityMapper.map_common_subexpression
+    def map_common_subexpression_uncached(self,
+                expr: prim.CommonSubexpression) -> Expression:
+        result = self.rec(expr.child)
+        if result is expr.child:
+            return expr
+
+        return type(expr)(
+                      result, expr.prefix, expr.scope, **expr.get_extra_properties())
 
 
 class DirectionalDerivative(DerivativeBase):