Bump github.com/sigstore/sigstore from 1.7.5 to 1.7.6

Bumps [github.com/sigstore/sigstore](https://github.com/sigstore/sigstore) from 1.7.5 to 1.7.6.
- [Release notes](https://github.com/sigstore/sigstore/releases)
- [Commits](sigstore/sigstore@v1.7.5...v1.7.6)

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

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

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/secure-systems-lab/go-securesystemslib v0.7.0
 	github.com/sigstore/protobuf-specs v0.2.1
 	github.com/sigstore/rekor v1.3.4
-	github.com/sigstore/sigstore v1.7.5
+	github.com/sigstore/sigstore v1.7.6
 	github.com/sigstore/timestamp-authority v1.2.0
 	github.com/stretchr/testify v1.8.4
 	github.com/theupdateframework/go-tuf v0.7.0

go.sum

@@ -416,8 +416,8 @@ github.com/sigstore/protobuf-specs v0.2.1 h1:KIoM7E3C4uaK092q8YoSj/XSf9720f8dlsb
 github.com/sigstore/protobuf-specs v0.2.1/go.mod h1:xPqQGnH/HllKuZ4VFPz/g+78epWM/NLRGl7Fuy45UdE=
 github.com/sigstore/rekor v1.3.4 h1:RGIia1iOZU7fOiiP2UY/WFYhhp50S5aUm7YrM8aiA6E=
 github.com/sigstore/rekor v1.3.4/go.mod h1:1GubPVO2yO+K0m0wt/3SHFqnilr/hWbsjSOe7Vzxrlg=
-github.com/sigstore/sigstore v1.7.5 h1:ij55dBhLwjICmLTBJZm7SqoQLdsu/oowDanACcJNs48=
-github.com/sigstore/sigstore v1.7.5/go.mod h1:9OCmYWhzuq/G4e1cy9m297tuMRJ1LExyrXY3ZC3Zt/s=
+github.com/sigstore/sigstore v1.7.6 h1:zB0woXx+3Bp7dk7AjklHF1VhXBdCs84VXkZbp0IHLv8=
+github.com/sigstore/sigstore v1.7.6/go.mod h1:FJE+NpEZIs4QKqZl4B2RtaVLVDcDtocAwTiNlexeBkY=
 github.com/sigstore/sigstore/pkg/signature/kms/aws v1.7.5 h1:ilufPp36exfpivctI3ElU4ZTckP3eVu6RxYebBb6u+M=
 github.com/sigstore/sigstore/pkg/signature/kms/aws v1.7.5/go.mod h1:121n8nBnuXbcI6K0hIBo/0EMYiyXqGVzbIYd0rV0ZWw=
 github.com/sigstore/sigstore/pkg/signature/kms/azure v1.7.5 h1:gLdNJJo+xMf7+IeFRlyA/Pjavndo9rivmf5ioYeuPmM=