Bump github.com/sigstore/protobuf-specs from 0.3.0 to 0.3.1 (#486)

Bumps [github.com/sigstore/protobuf-specs](https://github.com/sigstore/protobuf-specs) from 0.3.0 to 0.3.1.
- [Release notes](https://github.com/sigstore/protobuf-specs/releases)
- [Changelog](https://github.com/sigstore/protobuf-specs/blob/main/CHANGELOG.md)
- [Commits](sigstore/protobuf-specs@v0.3.0...v0.3.1)

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

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

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/secure-systems-lab/go-securesystemslib v0.8.0
 	github.com/sigstore/cosign/v2 v2.2.3
 	github.com/sigstore/fulcio v1.4.4
-	github.com/sigstore/protobuf-specs v0.3.0
+	github.com/sigstore/protobuf-specs v0.3.1
 	github.com/sigstore/rekor v1.3.6
 	github.com/sigstore/sigstore v1.8.3
 	github.com/spf13/cobra v1.8.0

go.sum

@@ -556,8 +556,8 @@ github.com/sigstore/cosign/v2 v2.2.3 h1:WX7yawI+EXu9h7S5bZsfYCbB9XW6Jc43ctKy/NoO
 github.com/sigstore/cosign/v2 v2.2.3/go.mod h1:WpMn4MBt0cI23GdHsePwO4NxhX1FOz1ITGB3ALUjFaI=
 github.com/sigstore/fulcio v1.4.4 h1:RjfymVe5t3a2CUBfLYo+7xEYuBusZa/XmFGxiYTsAqI=
 github.com/sigstore/fulcio v1.4.4/go.mod h1:yYtN6mvEFMSS/m7IM6+3rosUa30+0kgn4hIFbzZARZA=
-github.com/sigstore/protobuf-specs v0.3.0 h1:E49qS++llp4psM+3NNVEb+C4AD422bT9VkOQIPrNLpA=
-github.com/sigstore/protobuf-specs v0.3.0/go.mod h1:ynKzXpqr3dUj2Xk9O/5ZUhjnpi0F53DNi5AdH6pS3jc=
+github.com/sigstore/protobuf-specs v0.3.1 h1:9aJQrPq7iRDSLBNg//zsP7tAzxdHnD1sA+1FyCCrkrQ=
+github.com/sigstore/protobuf-specs v0.3.1/go.mod h1:HfkcPi5QXteuew4+c5ONz8vYQ8aOH//ZTQ3gg0X8ZUA=
 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 v1.8.3 h1:G7LVXqL+ekgYtYdksBks9B38dPoIsbscjQJX/MGWkA4=