Add support for writing Unix epoch-relative tracks to HLS, add proper cleanup of all Targets obtained by an Output

src/adts/adts-demuxer.ts

@@ -211,7 +211,7 @@ class AdtsAudioTrackBacking implements InputAudioTrackBacking {
 		return sampleRate / SAMPLES_PER_AAC_FRAME;
 	}
 
-	getTimestampsAreRelativeToUnixEpoch() {
+	isRelativeToUnixEpoch() {
 		return false;
 	}