OSGi Bundle specifies invalid require capability

[cziegeler]

The flexmark-osgi artifact for version 0.64.0 creates the following require capability:

Require-Capability osgi.ee;filter:="(osgi.ee=UNKNOWN)"

which is never fullfilled by an OSGi framework.

• [X] osgi
• [ ] HtmlRenderer
• [ ] Formatter
• [ ] FlexmarkHtmlParser
• [ ] DocxRenderer
• [ ] PdfConverterExtension
• [ ] extension(s)

This is caused by a very old maven bundle plugin when building with java 11 (or higher)