[GStreamer] Ignore early EOS only when not looping

https://bugs.webkit.org/show_bug.cgi?id=264398

Reviewed by Philippe Normand.

When playing video in a loop using HTML5 video element, the Gstreamer
debug log sometimes contains the following message, which prevents the
WPE from correctly stopping the playback before restarting it for the
next loop and the playback ends up paused forever:

```
webkitmediaplayer MediaPlayerPrivateGStreamer.cpp:1851:handleMessage:<video-1> EOS received but position {23823333333/1000000000 = 23.823333333} is still in the finite playable limits [{0/1 = 0}, {23828333333/1000000000 = 23.828333333}], ignoring it
```

Ignore early EOS only when not looping, otherwise unconditionally
indicate the stream has ended.

* Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:
(WebCore::MediaPlayerPrivateGStreamer::handleMessage):

Canonical link: https://commits.webkit.org/270593@main

Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp

@@ -1839,7 +1839,7 @@ void MediaPlayerPrivateGStreamer::handleMessage(GstMessage* message)
 
         if (GST_CLOCK_TIME_IS_VALID(gstreamerPosition))
             playbackPosition = MediaTime(gstreamerPosition, GST_SECOND);
-        if (!eosFlagIsSetInSink && playbackPosition.isValid() && duration.isValid()
+        if (!player->isLooping() && !eosFlagIsSetInSink && playbackPosition.isValid() && duration.isValid()
             && ((m_playbackRate >= 0 && playbackPosition < duration && duration.isFinite())
             || (m_playbackRate < 0 && playbackPosition > MediaTime::zeroTime()))) {
             GST_DEBUG_OBJECT(pipeline(), "EOS received but position %s is still in the finite playable limits [%s, %s], ignoring it",