Bump cloud.google.com/go/kms from 1.13.0 to 1.15.0

Bumps [cloud.google.com/go/kms](https://github.com/googleapis/google-cloud-go) from 1.13.0 to 1.15.0.
- [Release notes](https://github.com/googleapis/google-cloud-go/releases)
- [Changelog](https://github.com/googleapis/google-cloud-go/blob/main/documentai/CHANGES.md)
- [Commits](googleapis/google-cloud-go@kms/v1.13.0...kms/v1.15.0)

---
updated-dependencies:
- dependency-name: cloud.google.com/go/kms
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

go.mod

@@ -3,7 +3,7 @@ module go.step.sm/crypto
 go 1.18
 
 require (
-	cloud.google.com/go/kms v1.13.0
+	cloud.google.com/go/kms v1.15.0
 	filippo.io/edwards25519 v1.0.0
 	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.6.1
 	github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.3.0

go.sum

@@ -47,8 +47,8 @@ cloud.google.com/go/datastore v1.1.0/go.mod h1:umbIZjpQpHh4hmRpGhH4tLFup+FVzqBi1
 cloud.google.com/go/firestore v1.1.0/go.mod h1:ulACoGHTpvq5r8rxGJ4ddJZBZqakUQqClKRT5SZwBmk=
 cloud.google.com/go/iam v1.1.0 h1:67gSqaPukx7O8WLLHMa0PNs3EBGd2eE4d+psbO/CO94=
 cloud.google.com/go/iam v1.1.0/go.mod h1:nxdHjaKfCr7fNYx/HJMM8LgiMugmveWlkatear5gVyk=
-cloud.google.com/go/kms v1.13.0 h1:s+sRhcowXwuLsa2Z8g3Tmh5l0HWNBf//HogCgiuDs/0=
-cloud.google.com/go/kms v1.13.0/go.mod h1:c9J991h5DTl+kg7gi3MYomh12YEENGrf48ee/N/2CDM=
+cloud.google.com/go/kms v1.15.0 h1:xYl5WEaSekKYN5gGRyhjvZKM22GVBBCzegGNVPy+aIs=
+cloud.google.com/go/kms v1.15.0/go.mod h1:c9J991h5DTl+kg7gi3MYomh12YEENGrf48ee/N/2CDM=
 cloud.google.com/go/monitoring v0.1.0/go.mod h1:Hpm3XfzJv+UTiXzCG5Ffp0wijzHTC7Cv4eR7o3x/fEE=
 cloud.google.com/go/pubsub v1.0.1/go.mod h1:R0Gpsv3s54REJCy4fxDixWD93lHJMoZTyQ2kNxGRt3I=
 cloud.google.com/go/pubsub v1.1.0/go.mod h1:EwwdRX2sKPjnvnqCa270oGRyludottCI76h+R3AArQw=