[GStreamer] Do not link transcoder libraries with USE_GSTREAMER_FULL

https://bugs.webkit.org/show_bug.cgi?id=279114

Reviewed by Philippe Normand.

All gstreamer-related libraries are linked in via the single gstreamer-full library
when using USE_GSTREAMER_FULL. The `NOT USE_GSTREAMER_FULL` check is done for the
other gstreamer libraries but was missing for transcoder libraries.

* Source/WebCore/platform/GStreamer.cmake:

Canonical link: https://commits.webkit.org/283147@main

Source/WebCore/platform/GStreamer.cmake

@@ -63,9 +63,11 @@ if (ENABLE_VIDEO OR ENABLE_WEB_AUDIO)
 endif ()
 
 if (USE_GSTREAMER_TRANSCODER)
-    list(APPEND WebCore_LIBRARIES
-        ${GSTREAMER_TRANSCODER_LIBRARIES}
-    )
+    if (NOT USE_GSTREAMER_FULL)
+        list(APPEND WebCore_LIBRARIES
+            ${GSTREAMER_TRANSCODER_LIBRARIES}
+        )
+    endif ()
     list(APPEND WebCore_SYSTEM_INCLUDE_DIRECTORIES
         ${GSTREAMER_TRANSCODER_INCLUDE_DIRS}
     )