Drop the V1 plugin API compatibility code

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

src/Kaleidoscope/Syster.cpp

@@ -99,21 +99,6 @@ EventHandlerResult Syster::onKeyswitchEvent(Key &mapped_key, byte row, byte col,
   return EventHandlerResult::OK;
 }
 
-// Legacy V1 API
-
-#if KALEIDOSCOPE_ENABLE_V1_PLUGIN_API
-void Syster::begin() {
-  Kaleidoscope.useEventHandlerHook(legacyEventHandler);
-}
-
-Key Syster::legacyEventHandler(Key mapped_key, byte row, byte col, uint8_t key_state) {
-  EventHandlerResult r = ::Syster.onKeyswitchEvent(mapped_key, row, col, key_state);
-  if (r == EventHandlerResult::OK)
-    return mapped_key;
-  return Key_NoKey;
-}
-#endif
-
 }
 
 __attribute__((weak)) const char keyToChar(Key key) {

src/Kaleidoscope/Syster.h

@@ -43,16 +43,6 @@ class Syster : public kaleidoscope::Plugin {
 
   EventHandlerResult onKeyswitchEvent(Key &mapped_key, byte row, byte col, uint8_t keyState);
 
-#if KALEIDOSCOPE_ENABLE_V1_PLUGIN_API
-  kaleidoscope::EventHandlerResult onSetup() {
-    return kaleidoscope::EventHandlerResult::OK;
-  }
-
- protected:
-  void begin();
-  static Key legacyEventHandler(Key mapped_key, byte row, byte col, uint8_t key_state);
-#endif
-
  private:
   static char symbol_[SYSTER_MAX_SYMBOL_LENGTH + 1];
   static uint8_t symbol_pos_;