Fix go version in CI

[cmacknz]

Clean up the magefile, properly set the Go version used in CI, and upgrade containerd to fix dependabot alerts.

Same as elastic/elastic-agent-shipper#45

[elasticmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Start Time: 2022-06-06T21:27:52.575+0000

• Duration: 9 min 20 sec

Test stats 🧪

Test	Results
Failed	0
Passed	198
Skipped	0
Total	198

🤖 GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.