contrib: update mpg123 to 1.28.0

Quoting mpg123.de website:

"Fix misguided handling of part2_3_length checks in III_get_scale_factors_1() and III_get_scale_factors_2() which invalidated decoding of a mono source encoded as ms+i-stereo. This was a regression introduced with version 1.25.7."

Fixes #25798