ci: add depguard

[knqyf263]

Description

Add depguard to block some packages.

• golang.org/x/exp/slices => slices
• golang.org/x/exp/maps => maps or github.com/samber/lo (see maps: remove Keys and Values for Go 1.21 golang/go#61538)

Checklist

• I've read the guidelines for contributing to this repository.
• I've followed the conventions in the PR title.
• I've added tests that prove my fix is effective or that my feature works.
• I've updated the documentation with the relevant information (if needed).
• I've added usage information (if the PR introduces new options)
• I've included a "before" and "after" example to the description (if the PR is a user interface change).

[knqyf263]

I confirmed it works well.
https://github.com/aquasecurity/trivy/actions/runs/9578961655/job/26410346672?pr=6963

[knqyf263]

I didn't know maps.Keys and maps.Values have been removed...
golang/go#61538

[nikpivkin]

LGTM