chore(deps): bump google-cloud-pubsub from 0.16.0 to 0.30.0

Bumps [google-cloud-pubsub](https://github.com/yoshidan/google-cloud-rust) from 0.16.0 to 0.30.0.
- [Release notes](https://github.com/yoshidan/google-cloud-rust/releases)
- [Commits](https://github.com/yoshidan/google-cloud-rust/commits)

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

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.toml

@@ -60,7 +60,7 @@ murmur3 = { version = "0.5.2", optional = true }
 openssl = { version = "0.10", optional = true, features = ["vendored"] }
 lapin = { version = "2.2.1", optional = true }
 kafka = { version = "0.10.0", optional = true }
-google-cloud-pubsub = { version = "0.16.0", optional = true }
+google-cloud-pubsub = { version = "0.30.0", optional = true }
 google-cloud-googleapis = { version = "0.10.0", optional = true }
 google-cloud-default = { version = "0.4.0", optional = true, features = ["pubsub"] }
 jsonwebtoken = { version = "8.3.0", optional = true }