surfacetree: Revert "subsurfaceTree: assign surfaces to a CWLSurface"

This reverts commit 51b1b17fcb.

Crash issues, fixes #4874

src/helpers/SubsurfaceTree.cpp

@@ -145,7 +145,6 @@ void Events::listener_newSubsurfaceNode(void* owner, void* data) {
     const auto        PSUBSURFACE = (wlr_subsurface*)data;
 
     const auto        PNEWSUBSURFACE = &pNode->childSubsurfaces.emplace_back();
-    PNEWSUBSURFACE->surface.assign(PSUBSURFACE->surface);
 
     Debug::log(LOG, "Added a new subsurface {:x}", (uintptr_t)PSUBSURFACE);
 

src/helpers/SubsurfaceTree.hpp

@@ -36,7 +36,6 @@ struct SSurfaceTreeNode {
 
 struct SSubsurface {
     wlr_subsurface*   pSubsurface = nullptr;
-    CWLSurface        surface;
 
     SSurfaceTreeNode* pParent = nullptr;
     SSurfaceTreeNode* pChild  = nullptr;