Avoid leaking tickers

In Go 1.22 and earlier, a ticker needs to be explicitly stopped
when it's no longer useful in order to avoid a resource leak.
In Go 1.23 and later, an orphaned ticker will eventually be
garbage collected, but it's still more thrifty to stop it early.

examples/ortc-media/main.go

@@ -223,6 +223,7 @@ func fourCCToTrack(fourCC string) *webrtc.TrackLocalStaticSample {
 // Write a file to Track
 func writeFileToTrack(ivf *ivfreader.IVFReader, header *ivfreader.IVFFileHeader, track *webrtc.TrackLocalStaticSample) {
 	ticker := time.NewTicker(time.Millisecond * time.Duration((float32(header.TimebaseNumerator)/float32(header.TimebaseDenominator))*1000))
+	defer ticker.Stop()
 	for ; true; <-ticker.C {
 		frame, _, err := ivf.ParseNextFrame()
 		if errors.Is(err, io.EOF) {