finance/ticker: update to 4.5.6

• fix build on riscv64 by bumping golang.org/x/sys dependency to v0.5.0

Changelog: https://github.com/achannarasappa/ticker/releases/tag/v4.5.6

MFH: 2023Q1
Sponsored by: Berliner Linux User Group e.V.
Approved by: eduardo (mentor)
Differential Revision: https://reviews.freebsd.org/D38682