Bump github.com/google/go-containerregistry from 0.6.0 to 0.7.0 (#503)

Bumps [github.com/google/go-containerregistry](https://github.com/google/go-containerregistry) from 0.6.0 to 0.7.0.
- [Release notes](https://github.com/google/go-containerregistry/releases)
- [Changelog](https://github.com/google/go-containerregistry/blob/main/.goreleaser.yml)
- [Commits](google/go-containerregistry@v0.6.0...v0.7.0)

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

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

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

go.mod

@@ -3,31 +3,24 @@ module github.com/google/ko
 go 1.16
 
 require (
-	github.com/containerd/containerd v1.5.7 // indirect
-	github.com/containerd/stargz-snapshotter/estargz v0.9.0
-	github.com/cpuguy83/go-md2man/v2 v2.0.1 // indirect
+	github.com/containerd/stargz-snapshotter/estargz v0.10.0
 	github.com/docker/docker v20.10.10+incompatible
 	github.com/dprotaso/go-yit v0.0.0-20191028211022-135eb7262960
 	github.com/evanphx/json-patch/v5 v5.5.0 // indirect
 	github.com/fsnotify/fsnotify v1.5.1
 	github.com/go-training/helloworld v0.0.0-20200225145412-ba5f4379d78b
 	github.com/google/go-cmp v0.5.6
-	github.com/google/go-containerregistry v0.6.0
+	github.com/google/go-containerregistry v0.7.0
 	github.com/mattmoor/dep-notify v0.0.0-20190205035814-a45dec370a17
 	github.com/mattn/go-isatty v0.0.13 // indirect
 	github.com/opencontainers/image-spec v1.0.2-0.20210730191737-8e42a01fb1b7
 	github.com/spf13/cobra v1.2.1
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.9.0
-	golang.org/x/net v0.0.0-20211007125505-59d4e928ea9d // indirect
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
-	golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac // indirect
 	golang.org/x/text v0.3.7 // indirect
 	golang.org/x/time v0.0.0-20210723032227-1f47c861a9ac // indirect
 	golang.org/x/tools v0.1.7
-	google.golang.org/genproto v0.0.0-20211005153810-c76a74d43a8e // indirect
-	google.golang.org/grpc v1.41.0 // indirect
-	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
 	k8s.io/apimachinery v0.22.3
 	sigs.k8s.io/kind v0.11.1