message: Add `@awslabs/smithy-rs-server` as owners to `codegen-core`
diff: * @awslabs/rust-sdk-owners
  -/buildSrc/ @awslabs/rust-sdk-owners @crisidev @david-perez
  -/codegen-core/ @awslabs/rust-sdk-owners @crisidev @david-perez
  -/codegen-server/ @awslabs/smithy-rs-server
  +
  +# Server
  /codegen-server-test/ @awslabs/smithy-rs-server
  -/rust-runtime/aws-smithy-http-server/ @awslabs/smithy-rs-server
  +/codegen-server/ @awslabs/smithy-rs-server
  /rust-runtime/aws-smithy-http-server-python/ @awslabs/smithy-rs-server
  +/rust-runtime/aws-smithy-http-server/ @awslabs/smithy-rs-server
  -# Either team is able to modify this file to release new smithy-rs versions.
  -gradle.properties @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +# Shared ownership
  +/CHANGELOG.md @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +/CHANGELOG.next.toml @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +/README.md @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +/build.gradle.kts @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +/buildSrc/ @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +/codegen-core/ @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +/design/ @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +/gradle.properties @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  +/tools/ @awslabs/rust-sdk-owners @awslabs/smithy-rs-server
  