Remove incorrect inheritence of external for signals.

Author: amykyta3

src/systemrdl/__about__.py

@@ -1 +1 @@
-__version__ = "1.29.1"
+__version__ = "1.29.2"

src/systemrdl/core/elaborate.py

@@ -565,12 +565,8 @@ def enter_Field(self, node: FieldNode) -> None:
         node.inst.external = node.parent.inst.external
 
     def enter_Signal(self, node: SignalNode) -> None:
-        if isinstance(node.parent, RootNode):
-            # In root scope. External is meaningless, so assign it to False
-            node.inst.external = False
-        else:
-            assert node.parent is not None
-            node.inst.external = node.parent.inst.external
+        # External is meaningless for signals. Always False
+        node.inst.external = False
 
     def enter_Regfile(self, node: RegfileNode) -> None:
         if self.coerce_external_to is not None: