transcoder: Remove un-needed gst_init call

We can safely assume GStreamer is already initialized from here.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1840>

docs/meson.build

@@ -84,8 +84,7 @@ excludes = []
 foreach f: [
         'gst/frei0r/frei0r.h',
         'gst/mxf/mxful.c',
-        'gst-libs/gst/mpegts/gstmpegts-private.h',
-        'gst-libs/gst/player/*-private.h',
+        'gst-libs/gst/*/*-private.h',
         'gst-libs/gst/codecparsers/nalutils.h',
         'ext/closedcaption/bcd.h',
         'ext/closedcaption/bit_slicer.[ch]',

gst-libs/gst/transcoder/gsttranscoder.c

@@ -813,8 +813,6 @@ gst_transcoder_main (gpointer data)
 static gpointer
 gst_transcoder_init_once (G_GNUC_UNUSED gpointer user_data)
 {
-  gst_init (NULL, NULL);
-
   GST_DEBUG_CATEGORY_INIT (gst_transcoder_debug, "gst-transcoder", 0,
       "GstTranscoder");
   gst_transcoder_error_quark ();