Fix failing tests, add missing license headers

src/hls/hls-demuxer.ts

@@ -1,3 +1,11 @@
+/*!
+ * Copyright (c) 2026-present, Vanilagy and contributors
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
 import { AUDIO_CODECS, AudioCodec, inferCodecFromCodecString, MediaCodec, VIDEO_CODECS, VideoCodec } from '../codec';
 import { Demuxer, DurationMetadataRequestOptions } from '../demuxer';
 import { Input } from '../input';