deskutils/taskwarrior: Update to 2.5.1

• Update PORTVERSION and distinfo checksum (2.5.1)
• Add TEST_DEPENDS
• Remove patches (upstream)
• Update pkg-plist

https://github.com/taskwarrior/task/blob/2.5.1/ChangeLog

Reviewed by: skreuzer (maintainer)
Approved by: skreuzer (maintainer)
Differential Revision: D8380