Update idna_adapter requirement from =1.2.0 to =1.2.1

Updates the requirements on [idna_adapter](https://github.com/hsivonen/idna_adapter) to permit the latest version.
- [Commits](hsivonen/idna_adapter@v1.2.0...v1.2.1)

---
updated-dependencies:
- dependency-name: idna_adapter
  dependency-version: 1.2.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

lambda-runtime/Cargo.toml

@@ -75,7 +75,7 @@ hyper-util = { workspace = true, features = [
 ] }
 # pin back to pre-1.2.1 to avoid breaking rust MSRV of 1.81:
 # https://github.com/hsivonen/idna_adapter/commit/f948802e3a2ae936eec51886eefbd7d536a28791
-idna_adapter = "=1.2.0"
+idna_adapter = "=1.2.1"
 # Self dependency to enable the graceful-shutdown feature for tests
 lambda_runtime = { path = ".", features = ["tracing", "graceful-shutdown"] }
 pin-project-lite = { workspace = true }