Update attohttpc requirement from 0.28 to 0.29

Updates the requirements on [attohttpc](https://github.com/sbstp/attohttpc) to permit the latest version.
- [Release notes](https://github.com/sbstp/attohttpc/releases)
- [Commits](sbstp/attohttpc@v0.28.0...v0.29.0)

---
updated-dependencies:
- dependency-name: attohttpc
  dependency-type: direct:production
...

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

Cargo.toml

@@ -19,4 +19,4 @@ rust-version = "1.71.1"
 thiserror = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-attohttpc = { version = "0.28", features = ["json"] }
+attohttpc = { version = "0.29", features = ["json"] }