net-mgmt/thanos: Update 0.39.2 => 0.40.1

Changelogs:

• https://github.com/thanos-io/thanos/releases/tag/v0.40.0
• https://github.com/thanos-io/thanos/releases/tag/v0.40.1
• https://github.com/thanos-io/thanos/compare/v0.39.2...v0.40.0
• https://github.com/thanos-io/thanos/compare/v0.40.0...v0.40.1

Approved by: yuri@ (Mentor)
Differential Revision: https://reviews.freebsd.org/D53462