rpi-imager: unset qt style (#423043)

pkgs/by-name/rp/rpi-imager/package.nix

···
       (lib.cmakeBool "ENABLE_TELEMETRY" false)
     ];
 
+  qtWrapperArgs = [
+    "--unset QT_QPA_PLATFORMTHEME"
+    "--unset QT_STYLE_OVERRIDE"
+  ];
+
   passthru = {
     tests.version = testers.testVersion {
       package = finalAttrs.finalPackage;