BIM: Prevent crash when removing a wall's base component (#24633)

* BIM: Prevent crash when removing a wall's base component

When a user selected a wall's base object in the Tree View and used the
`Arch_Remove` command, a traceback occurred due to an `AttributeError`.

The `removeComponents` function was incorrectly checking for the `.Base`
attribute on a list of subtractions (`s.Base`) instead of on the parent
host object (`h.Base`).

This commit corrects the reference to check against the parent object,
resolving the crash and allowing the component to be removed.

Fixes: https://github.com/FreeCAD/FreeCAD/issues/24532

Authored-by:  furgo16 <148809153+furgo16@users.noreply.github.com>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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---------

Co-authored-by: Furgo <148809153+furgo16@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/Mod/BIM/ArchCommands.py

@@ -263,9 +263,10 @@ def removeComponents(objectsList, host=None):
                         s.remove(o)
                         h.Subtractions = s
                         o.ViewObject.show()
-                    elif o == s.Base:
-                        s.Base = None
-                        o.ViewObject.show()
+                    elif o == h.Base:
+                        h.Base = None
+                        if FreeCAD.GuiUp:
+                            o.ViewObject.show()
                 elif tp in ["SectionPlane"]:
                     a = h.Objects
                     if o in a: