build(deps): update cloudevents-sdk requirement from 0.8 to 0.9

Updates the requirements on [cloudevents-sdk](https://github.com/cloudevents/sdk-rust) to permit the latest version.
- [Release notes](https://github.com/cloudevents/sdk-rust/releases)
- [Commits](cloudevents/sdk-rust@0.8.0...0.9.0)

---
updated-dependencies:
- dependency-name: cloudevents-sdk
  dependency-version: 0.9.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

cdevents-sdk/Cargo.toml

@@ -11,7 +11,7 @@ rust-version.workspace = true
 description = "A Rust SDK for CDEvents"
 
 [dependencies]
-cloudevents-sdk = { version = "0.8", optional = true, default-features = false }
+cloudevents-sdk = { version = "0.9", optional = true, default-features = false }
 fluent-uri = "0.3"
 proptest = { version = "1.4", optional = true }
 proptest-derive = { version = "0.7", optional = true }