feat(deps): bump github.com/sigstore/sigstore from 1.8.9 to 1.8.10

Bumps [github.com/sigstore/sigstore](https://github.com/sigstore/sigstore) from 1.8.9 to 1.8.10.
- [Release notes](https://github.com/sigstore/sigstore/releases)
- [Commits](https://github.com/sigstore/sigstore/compare/v1.8.9...v1.8.10)

---
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

@@ -1,9 +1,6 @@
 module github.com/docker/attest
 
 go 1.22.7
-
-toolchain go1.22.8
-
 require (
 	github.com/Masterminds/semver/v3 v3.3.0
 	github.com/aws/aws-sdk-go-v2/config v1.27.43
@@ -22,7 +19,7 @@ require (
 	github.com/secure-systems-lab/go-securesystemslib v0.8.0
 	github.com/sigstore/cosign/v2 v2.4.1
 	github.com/sigstore/rekor v1.3.6
-	github.com/sigstore/sigstore v1.8.9
+	github.com/sigstore/sigstore v1.8.10
 	github.com/sigstore/sigstore/pkg/signature/kms/aws v1.8.9
 	github.com/sigstore/sigstore/pkg/signature/kms/gcp v1.8.9
 	github.com/stretchr/testify v1.9.0