Update dependency google-cloud-pubsub to v3

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
google-cloud-pubsub (source)	"2.23.0" → "3.4.0"

---

Release Notes

googleapis/google-cloud-ruby (google-cloud-pubsub)

v3.4.0: google-cloud-pubsub: v3.4.0

3.4.0 (2026-07-29)

Features

• implement streaming keep-alive logic (#​34653)

v3.3.0: google-cloud-pubsub: v3.3.0

3.3.0 (2026-06-11)

Features

• Upgrade to Ruby 3.2 minimum (#​33944)

v3.2.1: google-cloud-pubsub: v3.2.1

3.2.1 (2026-03-04)

Bug Fixes

• clean up warnings for pubsub veneer (#​32785)

v3.2.0: google-cloud-firestore: v3.2.0

3.2.0 (2026-05-07)

Features

• Update minimum Ruby to v3.2 and support v4.0 (#​33812)

v3.1.1: google-cloud-pubsub: v3.1.1

3.1.1 (2025-12-16)

Bug Fixes

• Remove get_topic lookup when publishing via lazy loading (#​32273)

v3.1.0: google-cloud-firestore: v3.1.0

3.1.0 (2025-08-07)

Features

• add AggregateQuery explanation features for RubyFirestore (#​30484)
• add Query explanation features for Ruby Firestore (#​29469)
• update routing headers to new format (#​30481)

v3.0.3: google-cloud-pubsub: v3.0.3

3.0.3 (2025-11-04)

Documentation

• add warning about loading unvalidated credentials (#​32121)

v3.0.2: google-cloud-pubsub: v3.0.2

3.0.2 (2025-08-12)

Bug Fixes

• Initialize topic_admin by default for the IAM client (#​30780)

Documentation

• Fix subscriber snippet in OVERVIEW.md (#​30813)

v3.0.1: google-cloud-pubsub: v3.0.1

3.0.1 (2025-08-07)

Documentation

• Update README.md to v3.x (#​30751)

v3.0.0: google-cloud-pubsub: v3.0.0

3.0.0 (2025-07-29)

⚠ BREAKING CHANGES

• The existing resource management API has been removed and replaced with the gRPC autogenerated surface. It includes CRUDL operations for topics, subscriptions, snapshots, and schemas as well as IAM. All legacy handwritten resource management classes are now deleted and operations will be performed via the generated clients.
• Rename Topic and Subscription to Publisher and Subscriber, which now serve as dedicated objects for sending and receiving messages.
• Remove Policy and RetryPolicy in favor of auto-generated counterparts (#​30725)
• Removal of legacy settings and parameters (e.g. use_legacy_flow_control, project, keyfile)

Features

• The existing resource management API has been removed and replaced with the gRPC autogenerated surface. It includes CRUDL operations for topics, subscriptions, snapshots, and schemas as well as IAM. All legacy handwritten resource management classes are now deleted and operations will be performed via the generated clients.
• Rename Topic and Subscription to Publisher and Subscriber, which now serve as dedicated objects for sending and receiving messages.
• Introduce path helper methods for accessing resources
• Removal of legacy settings and parameters (e.g. use_legacy_flow_control, project, keyfile)
• Remove Policy and RetryPolicy in favor of auto-generated counterparts (#​30725)
• Change default number of concurrent streams to 1 (#​30742)

---

Configuration

📅 Schedule: (UTC)

• Branch creation
  • At any time (no schedule defined)
• Automerge
  • At any time (no schedule defined)

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.