build(deps): bump github.com/opencontainers/image-spec (#2167)

Bumps [github.com/opencontainers/image-spec](https://github.com/opencontainers/image-spec) from 1.1.0-rc5 to 1.1.0-rc.6.
- [Release notes](https://github.com/opencontainers/image-spec/releases)
- [Changelog](https://github.com/opencontainers/image-spec/blob/main/RELEASES.md)
- [Commits](https://github.com/opencontainers/image-spec/compare/v1.1.0-rc5...v1.1.0-rc6)

---
updated-dependencies:
- dependency-name: github.com/opencontainers/image-spec
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -19,9 +19,9 @@ require (
 	github.com/julienschmidt/httprouter v1.3.0
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/mattn/go-isatty v0.0.20
-	github.com/moby/buildkit v0.12.5
+	github.com/moby/buildkit v0.11.5
 	github.com/moby/patternmatcher v0.6.0
-	github.com/opencontainers/image-spec v1.1.0-rc5
+	github.com/opencontainers/image-spec v1.1.0-rc.6
 	github.com/opencontainers/selinux v1.11.0
 	github.com/pkg/errors v0.9.1
 	github.com/rhysd/actionlint v1.6.26
@@ -42,7 +42,7 @@ require (
 	github.com/Microsoft/go-winio v0.6.1 // indirect
 	github.com/ProtonMail/go-crypto v0.0.0-20230828082145-3c4c8a2d2371 // indirect
 	github.com/cloudflare/circl v1.3.7 // indirect
-	github.com/containerd/containerd v1.7.11 // indirect
+	github.com/containerd/containerd v1.6.19 // indirect
 	github.com/cyphar/filepath-securejoin v0.2.4 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/distribution/reference v0.5.0 // indirect