Add changelog entry for FinalizationRegistry

Author: ketanhwr

src/content/changelog/workers/2025-04-24-finalization-registry.mdx

@@ -0,0 +1,11 @@
+---
+title: Improved Memory Efficiency for WebAssembly Workers
+description: With the introduction of FinalizationRegistry in Workers Runtime, toolchains like Emscripten and wasm-bindgen can automatically reclaim unused WebAssembly heap and reduce memory leaks.
+products:
+  - workers
+date: 2025-05-24T00:00:00Z
+---
+
+[FinalizationRegistry](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/FinalizationRegistry) is now available in Workers (opt-in with the `enable_weak_ref` compat flag), so toolchains such as Emscripten and wasm-bindgen can automatically free WebAssembly heap allocations.
+
+While this will reduce long-running memory growth and leaks to a certain extent, the API still depends on garbage-collector timing and other non-deterministic factors, so treat it as a helpful mitigation rather than a guaranteed fix.