fix: use _elements.remove() for kicad-skip collections lacking remove method

ElementCollection in kicad-skip doesn't implement remove(), causing
'WireCollection object has no attribute remove' errors. Access the
underlying _elements list directly for wire, label, and symbol deletion.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

python/commands/component_schematic.py

@@ -253,7 +253,7 @@ class ComponentManager:
                     break
 
             if symbol_to_remove:
-                schematic.symbol.remove(symbol_to_remove)
+                schematic.symbol._elements.remove(symbol_to_remove)
                 print(f"Removed component {component_ref} from schematic.")
                 return True
             else: