textproc/py-ocrmypdf: Update to 13.4.7
- Update WWW field to spare redirects.
Changelog since 13.4.2:
https://github.com/ocrmypdf/OCRmyPDF/blob/v13.4.7/docs/release_notes.rst
MFH: 2022Q2
(cherry picked from commit 124a6ff0ea302c64d24d5787d82a828fd5c6bdcc)