Bump github.com/containerd/containerd from 1.7.20 to 1.7.21

Bumps [github.com/containerd/containerd](https://github.com/containerd/containerd) from 1.7.20 to 1.7.21.
- [Release notes](https://github.com/containerd/containerd/releases)
- [Changelog](https://github.com/containerd/containerd/blob/main/RELEASES.md)
- [Commits](containerd/containerd@v1.7.20...v1.7.21)

---
updated-dependencies:
- dependency-name: github.com/containerd/containerd
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

go.mod

@@ -37,7 +37,7 @@ require (
 	github.com/bmatcuk/doublestar/v4 v4.6.1 // indirect
 	github.com/cenkalti/backoff/v4 v4.3.0 // indirect
 	github.com/cloudflare/circl v1.3.9 // indirect
-	github.com/containerd/containerd v1.7.20 // indirect
+	github.com/containerd/containerd v1.7.21 // indirect
 	github.com/containerd/errdefs v0.1.0 // indirect
 	github.com/containerd/log v0.1.0 // indirect
 	github.com/containerd/platforms v0.2.1 // indirect
@@ -96,6 +96,7 @@ require (
 	github.com/moby/patternmatcher v0.6.0 // indirect
 	github.com/moby/sys/sequential v0.6.0 // indirect
 	github.com/moby/sys/user v0.3.0 // indirect
+	github.com/moby/sys/userns v0.1.0 // indirect
 	github.com/moby/term v0.5.0 // indirect
 	github.com/morikuni/aec v1.0.0 // indirect
 	github.com/nwaples/rardecode v1.1.3 // indirect

go.sum

@@ -1177,8 +1177,8 @@ github.com/containerd/containerd v1.6.6/go.mod h1:ZoP1geJldzCVY3Tonoz7b1IXk8rIX0
 github.com/containerd/containerd v1.6.8/go.mod h1:By6p5KqPK0/7/CgO/A6t/Gz+CUYUu2zf1hUaaymVXB0=
 github.com/containerd/containerd v1.6.9/go.mod h1:XVicUvkxOrftE2Q1YWUXgZwkkAxwQYNOFzYWvfVfEfQ=
 github.com/containerd/containerd v1.7.0/go.mod h1:QfR7Efgb/6X2BDpTPJRvPTYDE9rsF0FsXX9J8sIs/sc=
-github.com/containerd/containerd v1.7.20 h1:Sl6jQYk3TRavaU83h66QMbI2Nqg9Jm6qzwX57Vsn1SQ=
-github.com/containerd/containerd v1.7.20/go.mod h1:52GsS5CwquuqPuLncsXwG0t2CiUce+KsNHJZQJvAgR0=
+github.com/containerd/containerd v1.7.21 h1:USGXRK1eOC/SX0L195YgxTHb0a00anxajOzgfN0qrCA=
+github.com/containerd/containerd v1.7.21/go.mod h1:e3Jz1rYRUZ2Lt51YrH9Rz0zPyJBOlSvB3ghr2jbVD8g=
 github.com/containerd/continuity v0.0.0-20190426062206-aaeac12a7ffc/go.mod h1:GL3xCUCBDV3CZiTSEKksMWbLE66hEyuu9qyDOOqM47Y=
 github.com/containerd/continuity v0.0.0-20190815185530-f2a389ac0a02/go.mod h1:GL3xCUCBDV3CZiTSEKksMWbLE66hEyuu9qyDOOqM47Y=
 github.com/containerd/continuity v0.0.0-20191127005431-f65d91d395eb/go.mod h1:GL3xCUCBDV3CZiTSEKksMWbLE66hEyuu9qyDOOqM47Y=
@@ -2450,6 +2450,8 @@ github.com/moby/sys/symlink v0.1.0/go.mod h1:GGDODQmbFOjFsXvfLVn3+ZRxkch54RkSiGq
 github.com/moby/sys/symlink v0.2.0/go.mod h1:7uZVF2dqJjG/NsClqul95CqKOBRQyYSNnJ6BMgR/gFs=
 github.com/moby/sys/user v0.3.0 h1:9ni5DlcW5an3SvRSx4MouotOygvzaXbaSrc/wGDFWPo=
 github.com/moby/sys/user v0.3.0/go.mod h1:bG+tYYYJgaMtRKgEmuueC0hJEAZWwtIbZTB+85uoHjs=
+github.com/moby/sys/userns v0.1.0 h1:tVLXkFOxVu9A64/yh59slHVv9ahO9UIev4JZusOLG/g=
+github.com/moby/sys/userns v0.1.0/go.mod h1:IHUYgu/kao6N8YZlp9Cf444ySSvCmDlmzUcYfDHOl28=
 github.com/moby/term v0.0.0-20200312100748-672ec06f55cd/go.mod h1:DdlQx2hp0Ss5/fLikoLlEeIYiATotOjgB//nb973jeo=
 github.com/moby/term v0.0.0-20210610120745-9d4ed1856297/go.mod h1:vgPCkQMyxTZ7IDy8SXRufE172gr8+K/JE/7hHFxHW3A=
 github.com/moby/term v0.0.0-20210619224110-3f7ff695adc6/go.mod h1:E2VnQOmVuvZB6UYnnDB0qG5Nq/1tD9acaOpo6xmt0Kw=