Bump github.com/google/go-containerregistry

Bumps [github.com/google/go-containerregistry](https://github.com/google/go-containerregistry) from 0.20.2 to 0.20.3.
- [Release notes](https://github.com/google/go-containerregistry/releases)
- [Changelog](https://github.com/google/go-containerregistry/blob/main/.goreleaser.yml)
- [Commits](google/go-containerregistry@v0.20.2...v0.20.3)

---
updated-dependencies:
- dependency-name: github.com/google/go-containerregistry
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

examples/oci-image-verification/go.mod

@@ -1,13 +1,12 @@
 module github.com/sigstore/sigstore-go/examples/oci-image-verification
 
 go 1.22.0
-
 toolchain go1.23.5
 
 replace github.com/sigstore/sigstore-go => ../../
 
 require (
-	github.com/google/go-containerregistry v0.20.2
+	github.com/google/go-containerregistry v0.20.3
 	github.com/sigstore/protobuf-specs v0.3.3
 	github.com/sigstore/sigstore v1.8.12
 	github.com/sigstore/sigstore-go v0.6.2

examples/oci-image-verification/go.sum

@@ -146,8 +146,6 @@ github.com/google/certificate-transparency-go v1.3.1 h1:akbcTfQg0iZlANZLn0L9xOeW
 github.com/google/certificate-transparency-go v1.3.1/go.mod h1:gg+UQlx6caKEDQ9EElFOujyxEQEfOiQzAt6782Bvi8k=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-github.com/google/go-containerregistry v0.20.2 h1:B1wPJ1SN/S7pB+ZAimcciVD+r+yV/l/DSArMxlbwseo=
-github.com/google/go-containerregistry v0.20.2/go.mod h1:z38EKdKh4h7IP2gSfUUqEvalZBqs6AoLeWfUy34nQC8=
 github.com/google/go-containerregistry v0.20.3 h1:oNx7IdTI936V8CQRveCjaxOiegWwvM7kqkbXTpyiovI=
 github.com/google/go-containerregistry v0.20.3/go.mod h1:w00pIgBRDVUDFM6bq+Qx8lwNWK+cxgCuX1vd3PIBDNI=
 github.com/google/gofuzz v1.2.0 h1:xRy4A+RhZaiKjJ1bPfwQ8sedCA+YS2YcCHW6ec7JMi0=