Set ObjectFile's assignment operator to also be deleted like its copy constructor (llvm#93072)

Reapply llvm#92942, this time
double checking it compiles. @vgvassilev, @compnerd.

Author: fsfod

llvm/include/llvm/Object/ObjectFile.h

@@ -302,6 +302,7 @@ class ObjectFile : public SymbolicFile {
 public:
   ObjectFile() = delete;
   ObjectFile(const ObjectFile &other) = delete;
+  ObjectFile &operator=(const ObjectFile &other) = delete;
 
   uint64_t getCommonSymbolSize(DataRefImpl Symb) const {
     Expected<uint32_t> SymbolFlagsOrErr = getSymbolFlags(Symb);