Bump flexmark-ext-gfm-tasklist from 0.61.16 to 0.61.20 (#6364)
Bump flexmark-ext-gfm-tasklist from 0.61.16 to 0.61.20 (#6364)

Bumps [flexmark-ext-gfm-tasklist](https://github.com/vsch/flexmark-java) from 0.61.16 to 0.61.20.
- [Release notes](https://github.com/vsch/flexmark-java/releases)
- [Commits](https://github.com/vsch/flexmark-java/compare/0.61.16...0.61.20)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>

Co-authored-by: dependabot-preview[bot] <6a4c1c4838f800d1998274cd5234e1f65c55e90c@users.noreply.github.com>
sauliusg/jabref,sauliusg/jabref,Siedlerchr/jabref,Siedlerchr/jabref,Siedlerchr/jabref,JabRef/jabref,sauliusg/jabref,JabRef/jabref,JabRef/jabref,Siedlerchr/jabref,sauliusg/jabref,JabRef/jabref