feat(core): mark linkedSignal API as public (#60865)

Follow up on the PR https://github.com/angular/angular/pull/60741

PR Close #60865

packages/core/src/render3/reactivity/linked_signal.ts

@@ -22,6 +22,8 @@ const identityFn = <T>(v: T) => v;
 
 /**
  * Creates a writable signal whose value is initialized and reset by the linked, reactive computation.
+ *
+ * @publicApi
  */
 export function linkedSignal<D>(
   computation: () => D,
@@ -34,7 +36,7 @@ export function linkedSignal<D>(
  *
  * Note: The computation is reactive, meaning the linked signal will automatically update whenever any of the signals used within the computation change.
  *
- * @developerPreview
+ * @publicApi
  */
 export function linkedSignal<S, D>(options: {
   source: () => S;