Bug 251060

For GTK/WPE ports, The cmake shows a duplicate USE_AVIF configuration message. I want to remove one.

-- Enabled features:
--  ENABLE_BUBBLEWRAP_SANDBOX ..................... ON
--  ENABLE_DOCUMENTATION                            ON
--  ENABLE_DRAG_SUPPORT ........................... ON
--  ENABLE_GAMEPAD                                  ON
--  ENABLE_GLES2 .................................. OFF
--  ENABLE_INTROSPECTION                            ON
--  ENABLE_JOURNALD_LOG ........................... ON
--  ENABLE_MEDIA_SOURCE                             ON
--  ENABLE_MINIBROWSER ............................ ON
--  ENABLE_PDFJS                                    ON
--  ENABLE_QUARTZ_TARGET .......................... OFF
--  ENABLE_SPELLCHECK                               ON
--  ENABLE_TOUCH_EVENTS ........................... ON
--  ENABLE_VIDEO                                    ON
--  ENABLE_WAYLAND_TARGET ......................... ON
--  ENABLE_WEBDRIVER                                ON
--  ENABLE_WEB_AUDIO .............................. ON
--  ENABLE_WEB_CRYPTO                               ON
--  ENABLE_X11_TARGET ............................. ON
--  USE_AVIF                                        ON
--  USE_AVIF ...................................... ON
--  USE_GBM                                         ON
--  USE_GTK4 ...................................... OFF
--  USE_JPEGXL                                      ON
--  USE_LCMS ...................................... ON
--  USE_LIBHYPHEN                                   ON
--  USE_LIBSECRET ................................. ON
--  USE_OPENGL_OR_ES                                ON
--  USE_OPENJPEG .................................. ON
--  USE_SOUP2                                       OFF
--  USE_WOFF2 ..................................... ON
-- Configuring done
-- Generating done
-- Build files have been written to: /app/webkit/WebKitBuild/Release