clean up tests a bit

test/unit/cmap/connection.test.ts

@@ -147,28 +147,13 @@ describe('new Connection()', function () {
     expect(error).to.have.property(beforeHandshakeSymbol, true);
   });
 
-  class MockSocket extends Socket {
-    override write(_data: string | Buffer) {
-      return false;
-    }
-    override _read() {
-      // do nothing
-    }
-
-    setTimeout() {
-      // do nothing
-    }
-
-    override on(event, handler) {
-      return super.on(event, handler);
-    }
-
-    override emit(event, ...args) {
-      return super.emit(event, ...args);
+  describe('NODE-6370: regression test', function () {
+    class MockSocket extends Socket {
+      override write(_data: string | Buffer) {
+        return false;
+      }
     }
-  }
 
-  describe.only('NODE-6370: regression test', function () {
     let socket: MockSocket;
     let connection: Connection;