[mlir] Deprecate NamedAttrList(std::nullopt_t) (NFC)#149544

kazutakahirata merged 1 commit intollvm:mainllvm/llvm-project:mainfrom

kazutakahirata:cleanup_20250718_mlir_NamedAttrList_nulloptkazutakahirata/llvm-project:cleanup_20250718_mlir_NamedAttrList_nulloptCopy head branch name to clipboard