build(deps): bump cloud.google.com/go/pubsub from 1.50.2 to 1.51.0 (#10453)

Bumps [cloud.google.com/go/pubsub](https://github.com/googleapis/google-cloud-go) from 1.50.2 to 1.51.0.
- [Release notes](https://github.com/googleapis/google-cloud-go/releases)
- [Changelog](https://github.com/googleapis/google-cloud-go/blob/main/CHANGES.md)
- [Commits](https://github.com/googleapis/google-cloud-go/compare/pubsub/v1.50.2...pubsub/v1.51.0)

---
updated-dependencies:
- dependency-name: cloud.google.com/go/pubsub
  dependency-version: 1.51.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

go.mod

@@ -4,7 +4,7 @@ go 1.25.8
 
 require (
 	cloud.google.com/go v0.123.0 // indirect
-	cloud.google.com/go/pubsub v1.50.2
+	cloud.google.com/go/pubsub v1.51.0
 	cloud.google.com/go/storage v1.64.0
 	github.com/Shopify/sarama v1.38.1
 	github.com/aws/aws-sdk-go v1.55.8
@@ -171,7 +171,7 @@ require (
 	atomicgo.dev/keyboard v0.2.9 // indirect
 	atomicgo.dev/schedule v0.1.0 // indirect
 	cloud.google.com/go/longrunning v1.2.0 // indirect
-	cloud.google.com/go/pubsub/v2 v2.5.1 // indirect
+	cloud.google.com/go/pubsub/v2 v2.6.0 // indirect
 	dario.cat/mergo v1.0.2 // indirect
 	github.com/Azure/azure-sdk-for-go/sdk/keyvault/internal v0.7.1 // indirect
 	github.com/Azure/go-ansiterm v0.0.0-20250102033503-faa5f7b0171c // indirect