[BUG]: Possible 3.1.0 regression when returning an object that has a copy constructor but no move constructor

[leakec]

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What version (or hash if on master) of pybind11 are you using?

3.1.0

Problem description

When returning an object that has a copy constructor, but no move constructor, I get a complier error in function_ref. This was not present in 3.0.4.

The code to produce the bug is given below. I've also included this tarball with all the files shown below to make re-producing the bug simple:
example.tar.gz

Reproducible example code

example.h

#pragma once

class A {
  public:
    A(int x_value) : x(x_value) {}

    A(const A &) = default;
    A &operator=(const A &) = delete;
    A(A &&) = delete;
    A &operator=(A &&) = delete;

    int x;
};

class B {
  public:
    A getA() const {
        return A(3);
    }
};

module.cc

#include "example.h"
#include <pybind11/pybind11.h>

namespace py = pybind11;

PYBIND11_MODULE(copy_elision_test, module) {
    py::class_<A>(module, "A").def_readonly("x", &A::x);

    py::class_<B>(module, "B").def(py::init<>()).def("getA", &B::getA);
}

CMakeLists.txt

# Builds and registers the minimal pybind11 copy-elision regression test.
cmake_minimum_required(VERSION 3.15)
project(pybind11_copy_elision_regression LANGUAGES CXX)

# Generate compile_commands.json for static-analysis tooling.
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

# Prefer an activated virtual environment when selecting the Python interpreter.
set(PYBIND11_FINDPYTHON ON)
set(Python_FIND_VIRTUALENV FIRST)
find_package(Python COMPONENTS Interpreter Development.Module REQUIRED)

# Ask the selected Python installation where its pybind11 CMake package lives.
execute_process(
    COMMAND "${Python_EXECUTABLE}" -m pybind11 --cmakedir
    OUTPUT_VARIABLE pybind11_DIR
    OUTPUT_STRIP_TRAILING_WHITESPACE
    COMMAND_ERROR_IS_FATAL ANY
)

# Use C++17 because guaranteed prvalue copy elision is the behavior under test.
find_package(pybind11 CONFIG REQUIRED)

pybind11_add_module(copy_elision_test module.cc)
target_compile_features(copy_elision_test PRIVATE cxx_std_17)
target_compile_options(copy_elision_test PRIVATE -Wall -Wextra -Wpedantic -Werror)

run_me - Shell script to run everything

#!/bin/bash

uv venv -p 3.12 .venv
source .venv/bin/activate

uv pip install pybind11==3.0.4
cmake -B build_3.0.4 -S .
cmake --build build_3.0.4

uv pip install pybind11==3.1.0
cmake -B build_3.1.0 -S .
cmake --build build_3.1.0

Is this a regression? Put the last known working version here if it is.

3.0.4