sysutils/dust: Update to v0.8.0

• Remove powerpc patch in crossbeab dependency: No longer needed after upstream PR 723 [1]

Changelog:

https://github.com/bootandy/dust/compare/v0.7.5...v0.8.0

[1] https://github.com/crossbeam-rs/crossbeam/pull/723

Reviewed_by: koobs
Differential_Revision: D34816
MFH: 2022Q2 (bug fixes and help texts improvements)