Remove log line to try to fix freeze on answering VoIP call (#7883)

The profiles point to some huge object being logged in VideoFeed's
playMedia() method, but this is the only log line added recently.
I can't see how this could possibly log anything huge, but not
sure what else to try, so let's try removing this as an experiment.
The bug it was added to diagnose seems to be fixed now anyway.

For element-hq/element-web#21181

src/components/views/voip/VideoFeed.tsx

@@ -137,7 +137,6 @@ export default class VideoFeed extends React.PureComponent<IProps, IState> {
             // them with another load() which will cancel the pending one, but since we don't call
             // load() explicitly, it shouldn't be a problem. - Dave
             await element.play();
-            logger.debug((this.props.feed.isLocal ? "Local" : "Remote") + " video feed play() completed");
         } catch (e) {
             logger.info("Failed to play media element with feed", this.props.feed, e);
         }