fix: linux, custom client, incoming only, resizable (#8005)

Signed-off-by: fufesou <shuanglongchen@yeah.net>

flutter/lib/main.dart

@@ -144,12 +144,8 @@ void runMainApp(bool startService) async {
     }
     windowManager.setOpacity(1);
     windowManager.setTitle(getWindowName());
-    // `windowManager.setResizable(false)` will reset the window size to the default size on Linux.
-    // https://stackoverflow.com/questions/8193613/gtk-window-resize-disable-without-going-back-to-default
-    if (!isLinux) {
-      windowManager.setResizable(!bind.isIncomingOnly());
-    }
-    // For Linux, we set the edge size to 0 to disable resize. See `get windowEdgeSize` in common.dart.
+    // Do not use `windowManager.setResizable()` here.
+    setResizable(!bind.isIncomingOnly());
   });
 }
 
@@ -243,7 +239,7 @@ void runConnectionManagerScreen() async {
   } else {
     await showCmWindow(isStartup: true);
   }
-  windowManager.setResizable(false);
+  setResizable(false);
   // Start the uni links handler and redirect links to Native, not for Flutter.
   listenUniLinks(handleByFlutter: false);
 }