[perf] prefer primitive over wrapped ints (flutter#8532)

**TL;DR:** no need for the wrapper type and it just gets unboxed a few lines later anyway.

Detected by a project inspection.

<img width="1572" height="272" alt="image" src="https://github.com/user-attachments/assets/4b8810c5-7ef9-4916-bd59-230c63c343e2" />

---

<details>
  <summary>Contribution guidelines:</summary><br>

- See our [contributor guide]([https://github.com/dart-lang/sdk/blob/main/CONTRIBUTING.md](https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview) for general expectations for PRs.
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Author: pq

src/io/flutter/run/daemon/DevToolsServerTask.java

@@ -216,7 +216,7 @@ private CompletableFuture<DevToolsInstance> checkForDartPluginInitiatedDevToolsW
 
     String[] parts = dartPluginUri.split(":");
     String host = parts[0];
-    Integer port = Integer.parseInt(parts[1]);
+    int port = Integer.parseInt(parts[1]);
     if (host == null) {
       return null;
     }