libopenmpt: update to 0.7.2.

OK wiz@

### libopenmpt 0.7.2 (2023-06-18)

*  [**New**] MOD: Can now read modified 8-channel MOD files from the DOS game
    Aleshar - The World Of Ice.

*  [**Sec**] Possible out-of-bounds read or write when reading malformed MED
    files. (r19389)

*  [**Bug**] The C++ API failed to compile with Clang/Emscripten in some
    situations due to a misplaced `[[deprecated]]`.
*  [**Bug**] The Opal OPL3 emulator symbols were not namespaced properly.
*  [**Bug**] Work-around for MSVC VS2022 17.6.0 ARM64 compiler bug.
*  [**Bug**] `Makefile` `CONFIG=emscripten EMSCRIPTEN_PORTS=1` failed to
    properly use `libogg` and `libvorbis` dependencies.

(fcambus)