Apply suggestions from code review

Author: lucascolley

src/metrology_apis/__init__.py

@@ -70,7 +70,7 @@ def __rtruediv__(self, other: Self, /) -> Self: ...
 
 
 @runtime_checkable
-class Unit[D: Dimension](Protocol):
+class Unit[D: Dimension = Any](Protocol):
     def __metrology_namespace__(
         self, /, *, api_version: str | None = None
     ) -> MetrologyNamespace[QT, VT, Self, D]:
@@ -110,7 +110,7 @@ def __rtruediv__(self, other: Self, /) -> Self: ...
 
 
 @runtime_checkable
-class Quantity[V = Any, U: UT = Any, D: Dimension = Any](Protocol):
+class Quantity[V: VT = Any, U: UT = Any, D: Dimension = Any](Protocol):
     def __metrology_namespace__(
         self, /, *, api_version: str | None = None
     ) -> MetrologyNamespace[Self, V, U, D]: