Fix Array from_buffer return type hint.

Author: esoma

Diff for: codegen/templates/_emath.pyi

@@ -232,7 +232,7 @@ class {{ type }}Array:
     @property
     def size(self) -> int: ...
     @classmethod
-    def from_buffer(cls, buffer: Any) -> {{ type }}: ...
+    def from_buffer(cls, buffer: Any) -> {{ type }}Array: ...
     @classmethod
     def get_component_type(cls) -> type[{{ type }}]: ...