Update module description

[tobiasdiez]

Hopefully, this should fix the MySql issue #5886 but I couldn't test it (have no MySql db running).
Maybe also the issue concerning the entry preview #5622 is fixed. At least there were some changes to require and provide statements concerning graal, and when running using gradlew run the preview were generated successfully.

• Change in CHANGELOG.md described (if applicable)
• Tests created for changes (if applicable)
• Manually tested changed features in running JabRef (always required)
• Screenshots added in PR description (for bigger UI changes)
• Checked documentation: Is the information available and up to date? If not: Issue created at https://github.com/JabRef/user-documentation/issues.

[Siedlerchr]

Doesn't work:

 /home/runner/work/jabref/jabref/build/jlinkbase/tmpjars/org.jabref.merged.module/module-info.java:1449: error: PluginHandler is not public in com.sun.webkit.plugin; cannot be accessed from outside package

    uses com.sun.webkit.plugin.PluginHandler;
> Task :createMergedModule
                              ^
/home/runner/work/jabref/jabref/build/jlinkbase/tmpjars/org.jabref.merged.module/module-info.java:1463: error: the service implementation type must be a subtype of the service interface type, or have a public static no-args method named "provider" returning the service implementation
    provides javax.xml.bind.JAXBContext with com.sun.xml.bind.v2.ContextFactory;
                                                                ^
2 errors


FAILURE: Build failed with an exception.
> Task :createMergedModule FAILED