opus: Update to version 1.4

opus: Update to version 1.4

- Updsate from version 1.3.1 to 1.4
- Update of rootfile
- Changelog
    opus 1.4 major release brings the following improvements and fixes:
	    Improved tuning of the Opus in-band FEC (LBRR).
             See https://gitlab.xiph.org/xiph/opus/-/issues/2360 for details
	    Added a OPUS_SET_INBAND_FEC(2) option that turns on FEC, but does not force
             SILK mode (FEC will be disabled in CELT mode)
	    Improved tuning and various fixes to DTX
	    Added Meson support, improved CMake support In addition to the improvements
             above, this release includes many minor bug fixes.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>