MIDI: Fix basic noteon: send correct velocity (#6476)

quantum/process_keycode/process_midi.c

@@ -24,7 +24,7 @@
 
 void process_midi_basic_noteon(uint8_t note)
 {
-    midi_send_noteon(&midi_device, 0, note, 128);
+    midi_send_noteon(&midi_device, 0, note, 127);
 }
 
 void process_midi_basic_noteoff(uint8_t note)