To avoid having to fixup half a dozen places where we're creating PDF
writers, and possibly ending up with new ill-configured writers in
the future, patch PyPDF2's own writer with a subclass setting /Creator
and /Producer.
Note that this will not affect non-post-processed PDFs generated by
wkhtmltopdf. wkhtmltopdf does not allow setting these properties[0][1], so
to fix this issue we'd have to alter _run_wkhtmltopdf to pass the
result through PyPDF2 in order to alter its metadata.
[0] https://github.com/wkhtmltopdf/wkhtmltopdf/issues/2000
[1] https://bugreports.qt.io/browse/QTBUG-44451closesodoo/odoo#29460
Signed-off-by: Xavier Morel (xmo) <xmo@odoo.com>