Some compilation options are for amd64 only, doesn't work on arm64

[athoune]

On a tiny Hetzner ARM instance, a simple pip install . raises an error :

Building wheels for collected packages: whispercpp
  Building wheel for whispercpp (pyproject.toml) ... error
  error: subprocess-exited-with-error

  × Building wheel for whispercpp (pyproject.toml) did not run successfully.
  │ exit code: 1
  ╰─> [5 lines of output]
      aarch64-linux-gnu-gcc: error: unrecognized command-line option ‘-mavx’
      aarch64-linux-gnu-gcc: error: unrecognized command-line option ‘-mavx2’
      aarch64-linux-gnu-gcc: error: unrecognized command-line option ‘-mfma’
      aarch64-linux-gnu-gcc: error: unrecognized command-line option ‘-mf16c’
      error: command '/usr/bin/aarch64-linux-gnu-gcc' failed with exit code 1
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
  ERROR: Failed building wheel for whispercpp