3.9
ODT reader: Add table row and column spans (#11366)
HTML writer: Include all classes on highlighted code elements.
Update copyright dates to 2024.
Add `xlsx` (Microsoft Excel) as an input format.
Prefer MIME type when determining extensions for MediaBag items (#10557)
Add asciidoc as an input format.
Avoid use of 'head' in Tests.Shared.
New `xml` format exactly representing a Pandoc AST.