devel/arduino-irremote: Update to 2.8.1. Changes since 2.5.0:

• ESP32 bug fixed, corrected Samsung timing, NEC repeat implementation.
• Adjusted JVC and LG timing, fixed 4809 bug.
• Major refactoring, new functions, repeat handling, NRF5 support.
• Changed License to MIT, ATtiny timer 1 support Removed AIWA + Mitsubishi, example IR2Keyboard.