Bump github.com/sigstore/sigstore from 1.8.8 to 1.8.9

Bumps [github.com/sigstore/sigstore](https://github.com/sigstore/sigstore) from 1.8.8 to 1.8.9.
- [Release notes](https://github.com/sigstore/sigstore/releases)
- [Commits](sigstore/sigstore@v1.8.8...v1.8.9)

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

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

go.mod

@@ -24,7 +24,7 @@ require (
 	github.com/sigstore/fulcio v1.6.3
 	github.com/sigstore/policy-controller v0.10.0
 	github.com/sigstore/rekor v1.3.6
-	github.com/sigstore/sigstore v1.8.8
+	github.com/sigstore/sigstore v1.8.9
 	github.com/transparency-dev/merkle v0.0.2
 	go.uber.org/ratelimit v0.3.1
 	golang.org/x/oauth2 v0.22.0

go.sum

@@ -845,8 +845,8 @@ github.com/sigstore/protobuf-specs v0.3.2 h1:nCVARCN+fHjlNCk3ThNXwrZRqIommIeNKWw
 github.com/sigstore/protobuf-specs v0.3.2/go.mod h1:RZ0uOdJR4OB3tLQeAyWoJFbNCBFrPQdcokntde4zRBA=
 github.com/sigstore/rekor v1.3.6 h1:QvpMMJVWAp69a3CHzdrLelqEqpTM3ByQRt5B5Kspbi8=
 github.com/sigstore/rekor v1.3.6/go.mod h1:JDTSNNMdQ/PxdsS49DJkJ+pRJCO/83nbR5p3aZQteXc=
-github.com/sigstore/sigstore v1.8.8 h1:B6ZQPBKK7Z7tO3bjLNnlCMG+H66tO4E/+qAphX8T/hg=
-github.com/sigstore/sigstore v1.8.8/go.mod h1:GW0GgJSCTBJY3fUOuGDHeFWcD++c4G8Y9K015pwcpDI=
+github.com/sigstore/sigstore v1.8.9 h1:NiUZIVWywgYuVTxXmRoTT4O4QAGiTEKup4N1wdxFadk=
+github.com/sigstore/sigstore v1.8.9/go.mod h1:d9ZAbNDs8JJfxJrYmulaTazU3Pwr8uLL9+mii4BNR3w=
 github.com/sigstore/sigstore-go v0.5.1 h1:5IhKvtjlQBeLnjKkzMELNG4tIBf+xXQkDzhLV77+/8Y=
 github.com/sigstore/sigstore-go v0.5.1/go.mod h1:TuOfV7THHqiDaUHuJ5+QN23RP/YoKmsbwJpY+aaYPN0=
 github.com/sigstore/sigstore/pkg/signature/kms/aws v1.8.8 h1:2zHmUvaYCwV6LVeTo+OAkTm8ykOGzA9uFlAjwDPAUWM=