Problem to delete pages on PDF

[Dayof]

Description of the bug

I tried to delete pages using delete_pages() but it seems to not have effect when calling tobytes().
I cannot use insert_pdf() to create a new document without the pages as well because of the problem below:
#3315

How to reproduce the bug

>>> import pymupdf
>>> with open("Marco_Aurelio_Meditaciones_02_pages.pdf", "rb") as f:
...     pdf_content = f.read()
... 
>>> file_copy = pymupdf.open("pdf", pdf_content)
>>> page_to_keep = 0
>>> pages_to_delete = [i for i in range(len(file_copy)) if i != page_to_keep]
>>> file_copy.delete_pages(pages_to_delete)
>>> print(f"After deletion: {len(file_copy)} pages")
After deletion: 1 pages
>>> result_bytes = file_copy.tobytes()
>>> result_doc = pymupdf.open("pdf", result_bytes)
>>> print(f"Result document has {len(result_doc)} pages")
Result document has 2 pages

This is the document:
Marco_Aurelio_Meditaciones_02_pages.pdf

PyMuPDF version

1.26.3

Operating system

Linux

Python version

3.11

[JorjMcKie]

This problem has nothing to do with whether the PDF is in memory or not.
Even when the PDF is opened from disk and other page deletion forms are used, e.g. del doc[1] will not work.
... Investigating ...