build(deps): bump github.com/coreos/butane from 0.19.0 to 0.21.0

Bumps [github.com/coreos/butane](https://github.com/coreos/butane) from 0.19.0 to 0.21.0.
- [Release notes](https://github.com/coreos/butane/releases)
- [Changelog](https://github.com/coreos/butane/blob/main/docs/release-notes.md)
- [Commits](coreos/butane@v0.19.0...v0.21.0)

---
updated-dependencies:
- dependency-name: github.com/coreos/butane
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

go.mod

@@ -17,7 +17,7 @@ require (
 	github.com/aliyun/alibaba-cloud-sdk-go v1.61.1442
 	github.com/aliyun/aliyun-oss-go-sdk v2.0.3+incompatible
 	github.com/aws/aws-sdk-go v1.53.5
-	github.com/coreos/butane v0.19.0
+	github.com/coreos/butane v0.21.0
 	github.com/coreos/go-semver v0.3.1
 	github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e
 	github.com/coreos/go-systemd/v22 v22.5.0

go.sum

@@ -57,8 +57,8 @@ github.com/containers/image/v5 v5.28.0 h1:H4cWbdI88UA/mDb6SxMo3IxpmS1BSs/Kifvhwt
 github.com/containers/image/v5 v5.28.0/go.mod h1:9aPnNkwHNHgGl9VlQxXEshvmOJRbdRAc1rNDD6sP2eU=
 github.com/containers/storage v1.50.1 h1:1r5k4N2BNa94WZZFw116tozj08zJg7SxihQZ3iccyCs=
 github.com/containers/storage v1.50.1/go.mod h1:dpspZsUrcKD8SpTofvKWhwPDHD0MkO4Q7VE+oYdWkiA=
-github.com/coreos/butane v0.19.0 h1:F4uuWwIaOCA6YrBOKoVU1cb25SMIkuValW9p1/PXyO8=
-github.com/coreos/butane v0.19.0/go.mod h1:dfa3/aWa58qfWMK/CGm3OR3T328x6x2nm66MgZURCTs=
+github.com/coreos/butane v0.21.0 h1:GDi6XBheEfvxaq7Ez3wxdN+0IraAz3U7QvpVGcbHd84=
+github.com/coreos/butane v0.21.0/go.mod h1:3OKS5qaH58O2yLAKgAtOgBpUQSm7aIOU09IpG+IvmF4=
 github.com/coreos/go-json v0.0.0-20230131223807-18775e0fb4fb h1:rmqyI19j3Z/74bIRhuC59RB442rXUazKNueVpfJPxg4=
 github.com/coreos/go-json v0.0.0-20230131223807-18775e0fb4fb/go.mod h1:rcFZM3uxVvdyNmsAV2jopgPD1cs5SPWJWU5dOz2LUnw=
 github.com/coreos/go-semver v0.3.1 h1:yi21YpKnrx1gt5R+la8n5WgS0kCrsPp33dmEyHReZr4=