mail/py-offlineimap: Update 8.0.2 => 8.0.3

While here, add new DOCS dependency and drop backported patch
since it's included in this release already.

Changelog:
https://github.com/OfflineIMAP/offlineimap3/blob/v8.0.3/Changelog.md
Commit log:
https://github.com/OfflineIMAP/offlineimap3/compare/v8.0.2...v8.0.3

PR: 296060
Approved by: osa, vvd (Mentors, implicit)