chore: config dtk animations

set/unset `D_DTK_DISABLE_ANIMATIONS` according to the dconfig

src/kernel/dguiapplicationhelper.cpp

@@ -115,6 +115,7 @@ Q_GLOBAL_STATIC(DFontManager, _globalFM)
 #define WINDOW_THEME_KEY "_d_platform_theme"
 
 #define APP_THEME_TYPE "themeType"
+#define DTK_ENABLE_ANIMATIONS "enableDtkAnimations"
 Q_GLOBAL_STATIC_WITH_ARGS(DTK_CORE_NAMESPACE::DConfig, _d_dconfig, ("org.deepin.dtk.preference"));
 
 /*!
@@ -529,7 +530,14 @@ DGuiApplicationHelper::DGuiApplicationHelper()
     : QObject(nullptr)
     , DObject(*new DGuiApplicationHelperPrivate(this))
 {
+    if (_d_dconfig.exists())
+        return;
 
+    if (_d_dconfig->value(DTK_ENABLE_ANIMATIONS, false).toBool()) {
+        qunsetenv("D_DTK_DISABLE_ANIMATIONS");
+    } else {
+        qputenv("D_DTK_DISABLE_ANIMATIONS", "1");
+    }
 }
 
 void DGuiApplicationHelper::initialize()