(test): exclude TCP adapter from coverage — runtime-only code

Adapter/TCP.php is 80% Swoole coroutine client code (getConnection,
activateSockmap, applySocketOptions) that needs a live server. The
testable surface (protocol detection, setters) is already covered
by TCPAdapterExtendedTest.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: abnegate

phpunit.xml

@@ -16,6 +16,7 @@
         <exclude>
             <directory>src/Server</directory>
             <directory>src/Sockmap</directory>
+            <file>src/Adapter/TCP.php</file>
         </exclude>
     </source>
 </phpunit>