Reduce needless precision in audio note frequency calculation (#21496)

quantum/process_keycode/process_audio.c

@@ -13,7 +13,7 @@ float voice_change_song[][2] = VOICE_CHANGE_SONG;
 
 float compute_freq_for_midi_note(uint8_t note) {
     // https://en.wikipedia.org/wiki/MIDI_tuning_standard
-    return pow(2.0, (note - 69) / 12.0) * PITCH_STANDARD_A;
+    return powf(2.0f, (note - 69) / 12.0f) * PITCH_STANDARD_A;
 }
 
 bool process_audio(uint16_t keycode, keyrecord_t *record) {