chore(deps): update rig-core requirement from 0.14.0 to 0.15.1 (#327)

Updates the requirements on [rig-core](https://github.com/0xPlaygrounds/rig) to permit the latest version.
- [Release notes](https://github.com/0xPlaygrounds/rig/releases)
- [Commits](https://github.com/0xPlaygrounds/rig/compare/rig-core-v0.14.0...rig-core-v0.15.1)

---
updated-dependencies:
- dependency-name: rig-core
  dependency-version: 0.15.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: jokemanfire <hu.dingyang@zte.com.cn>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

examples/rig-integration/Cargo.toml

@@ -13,7 +13,7 @@ readme = { workspace = true }
 publish = false
 
 [dependencies]
-rig-core = "0.14.0"
+rig-core = "0.15.1"
 tokio = { version = "1", features = ["full"] }
 rmcp = { workspace = true, features = [
     "client",