Adjust debounce and change algorithm

- board can handle sym_defer_pk
- revert debounce to 2ms for algorithm change

keyboards/nuphy/air75_v2/ansi/customizations.md

@@ -18,7 +18,7 @@ This is a deep sleep state. There are no indicators in other sleep modes.
 - Bluetooth connection indicators will be lit blue when establishing connection. This lights the corresponding
 BT mode key. No indicator for RF as the sidelight is a different colour.
 - Default startup LED brightness set to zero and side led set to lowest brightness. This is because I don't use LEDs so I don't need to toggle them off when resetting the board or flashing new firmware.
-- 3ms debounce instead of 2ms (potential stability)
+- Change debounce algorithm to `sym_defer_pk`. MCU should be fast enough to handle this.
 - 3 sleep modes (inspired by @adi4086) - Toggle sleep mode button moved to `Fn + M + ]`.
   - Deep Sleep (NRF off, MCU off, LED off) - lowest power consumption. This is the default. Right indicator blinks green.
   - Light Sleep (NRF off, LED off) - no real reason to use this, but might wake up quicker. Right indicator blinks yellow.

keyboards/nuphy/air75_v2/ansi/info.json

@@ -25,7 +25,11 @@
     },
     "processor": "STM32F072",
     "bootloader": "stm32-dfu",
-    "debounce": 3,
+    "debounce": 2,
+    "build": {
+        "debounce_type": "sym_defer_pk",
+        "lto": true
+    },
     "matrix_pins": {
         "cols": ["A4", "A5", "A6", "B9", "B0", "B1", "B10", "B11", "B12", "B13", "B14", "B15", "A8", "A9", "A10", "A15", "B3"],
         "rows": ["C14", "C15", "A0", "A1", "A2", "A3"]