Read-only archives not always closed when the workbook is closed on Windows

When opening a workbook in read-only mode AND reading a value from a cell, AND the cell is not empty, a file handle is leaked. If the cell is empty, or if the workbook is empty, or if we don't use read-only mode, the problem goes away. If we don't try to clean up our temporary files, the problem is still there, but hidden.

def problem() -> None:
    book_path = Path("value.xlsx")
    tmp_book_path = Path("tmp.xlsx")
    copyfile(src=book_path, dst=tmp_book_path)

    book: Workbook = load_workbook(
        filename=tmp_book_path,
        read_only=True,  # Changing this to False makes the problem go away.
        data_only=True,
    )

    # Commenting out the next line or changing "A1" to "A2" makes the
problem go away.
    print(book["Sheet1"]["A1"].value)

    book.close()

    # This fails because something is still using the file.
    tmp_book_path.unlink(missing_ok=True)

empty.xlsx and value.xlsx are attached

In practice, our code looks closer to this:

from pathlib import Path
from shutil import copyfile
from openpyxl import load_workbook, Workbook

def problem():
    wb = Workbook()
    wb.save("value.xlsx")
    wb.close()
    
    book_path = Path("value.xlsx")
    tmp_book_path = Path("tmp.xlsx")
    copyfile(src=book_path, dst=tmp_book_path)

    book = load_workbook(
        filename=tmp_book_path,
        read_only=True,  # Changing this to False makes the problem go away.
        data_only=True,
    )

    # Commenting out the next line or changing "A1" to "A2" makes the problem go away.
    print(book["Sheet"]["A1"].value)

    book.close()

    # This fails because something is still using the file.
    tmp_book_path.unlink(missing_ok=True)


if __name__ == "__main__":
    problem()