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

Bumps [github.com/opencontainers/image-spec](https://github.com/opencontainers/image-spec) from 1.1.0-rc1 to 1.1.0-rc2.
- [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-rc1...v1.1.0-rc2)

---
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>

vendor/github.com/opencontainers/image-spec/specs-go/v1/artifact.go

@@ -26,8 +26,8 @@ type Artifact struct {
 	// Blobs is a collection of blobs referenced by this manifest.
 	Blobs []Descriptor `json:"blobs,omitempty"`
 
-	// Refers is an optional link to any existing manifest within the repository.
-	Refers *Descriptor `json:"refers,omitempty"`
+	// Subject (reference) is an optional link from the artifact to another manifest forming an association between the artifact and the other manifest.
+	Subject *Descriptor `json:"subject,omitempty"`
 
 	// Annotations contains arbitrary metadata for the artifact manifest.
 	Annotations map[string]string `json:"annotations,omitempty"`

vendor/github.com/opencontainers/image-spec/specs-go/v1/manifest.go

@@ -30,8 +30,8 @@ type Manifest struct {
 	// Layers is an indexed list of layers referenced by the manifest.
 	Layers []Descriptor `json:"layers"`
 
-	// Refers is an optional link to any existing manifest within the repository.
-	Refers *Descriptor `json:"refers,omitempty"`
+	// Subject is an optional link from the image manifest to another manifest forming an association between the image manifest and the other manifest.
+	Subject *Descriptor `json:"subject,omitempty"`
 
 	// Annotations contains arbitrary metadata for the image manifest.
 	Annotations map[string]string `json:"annotations,omitempty"`

vendor/github.com/opencontainers/image-spec/specs-go/version.go

@@ -25,7 +25,7 @@ const (
 	VersionPatch = 0
 
 	// VersionDev indicates development branch. Releases will be empty string.
-	VersionDev = "-rc1"
+	VersionDev = "-rc2"
 )
 
 // Version is the specification version that the package types support.