Bump github.com/containerd/containerd from 1.6.1 to 1.6.18

Bumps [github.com/containerd/containerd](https://github.com/containerd/containerd) from 1.6.1 to 1.6.18.
- [Release notes](https://github.com/containerd/containerd/releases)
- [Changelog](https://github.com/containerd/containerd/blob/main/RELEASES.md)
- [Commits](containerd/containerd@v1.6.1...v1.6.18)

---
updated-dependencies:
- dependency-name: github.com/containerd/containerd
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/aws/aws-sdk-go v1.15.31
 	github.com/bitly/go-simplejson v0.5.0
 	github.com/cenk/backoff v2.1.0+incompatible
-	github.com/containerd/containerd v1.6.1 // indirect
+	github.com/containerd/containerd v1.6.18 // indirect
 	github.com/docker/docker v20.10.13+incompatible
 	github.com/docker/go-connections v0.4.0
 	github.com/dustin/go-humanize v1.0.0