Update deps

[arl]

❓ What

Update some important dependencies, not all of them but those with security fixes and those that are way behind.

• bump github.com/charmbracelet/glamour to v0.6.0
• bump github.com/DataDog/datadog-go/v5 to v0.5.1
• bump github.com/juju/ratelimit to v1.0.2
• bump github.com/valyala/gozstd to v1.17.0
• bump golang.org/x/net to v0.4.0
• bump required go version to 1.18

🔨 How to test

1. List all steps necessary;
2. To test this pull request.

✅ Checklists

This section contains a list of checklists for common uses, please delete the checklists that are useless for your current use case (or add another checklist if your use case isn't covered yet).

• Is there unit/integration test coverage for all new and/or changed functionality added in this PR?
• Have the changes in this PR been functionally tested?
• Have new components been added to the related all.go files?
• Have new components been added to the documentation website?
• Has make gofmt-write been run on the code?
• Has make govet been run on the code? Has the code been fixed accordingly to the output?
• Have the changes been added to the CHANGELOG.md file?
• Have the steps in CONTRIBUTING.md been followed to update a Go module?