autotests: Add breeze-icons to .kde-ci.yml

Some tests need it, e.g.

FAIL!  : TestXdgShellClient::testDesktopFileName() Compared values are not the same
   Actual   (c->icon().name())         : ""
   Expected (QStringLiteral("wayland")): "wayland"

.kde-ci.yml

@@ -4,6 +4,7 @@
 Dependencies:
 - 'on': ['@all']
   'require':
+    'frameworks/breeze-icons': '@stable'
     'frameworks/extra-cmake-modules': '@stable'
     'frameworks/kconfig': '@stable'
     'frameworks/kconfigwidgets': '@stable'