Swift Generated Code: Add @unchecked Sendable conformance to classes that conform to FeatureManifestInterface (#6963)

* Add `@unchecked Sendable` conformance to classes that conform to `FeatureManifestInterface`.

* Update changelog.

Author: ih-codes

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 [Full Changelog](In progress)
 
+### Swift
+- Added `@unchecked Sendable` to classes that conform to `FeatureManifestInterface`. ([#6963](https://github.com/mozilla/application-services/pull/6963)
+
 # v144.0 (_2025-09-15_)
 
 ## ✨ What's New ✨

components/support/nimbus-fml/src/backends/swift/templates/FeatureManifestTemplate.swift

@@ -13,7 +13,7 @@
 /// An object for safely accessing feature configuration from Nimbus.
 ///
 /// This is generated.
-public class {{ nimbus_object }} : FeatureManifestInterface {
+public class {{ nimbus_object }} : FeatureManifestInterface, @unchecked Sendable {
     public typealias Features = {{ features_object }}
 
     ///