Log Message:
audio/fasttracker2: Update to 1.91

While here switch to using devel/cmake/build.mk.

Changes since 1.89:

v1.91 - 10.12.2024
- Critical fix: Fixed a position/playback problem with voices/channels running
  at volume zero. This bug appeared in v1.87 (03.11.2024).
- Windows/macOS: Updated SDL to v2.30.10

v1.90 - 09.12.1024
- Fixed: The Nibbles game broke in v1.89 (snake food was no longer visible)