Add Sinc Rev. 3 (#18846)

* Initial work on adding Sinc Rev. 3

* Add RGB Matrix support

* Add encoder map support

* Set I2C pins

* Update LED locations for right half

* Move USB definitions to info.json

* Update RGB modes

* Replace pin mappings for right half with correct ones

* Move config.h back to rev1/rev2 due to addition of rev3

* Convert initial Rev. 3 config work to be data-driven

* Convert RGB Matrix config to DD format

* More config cleanup

* Use full-duplex PIO

* Add MCU/bootloader settings for Rev. 2

* Change ISO Enter location since it shares location with Backslash

* Adjust build settings to reduce flash/EEPROM usage

keyboards/keebio/sinc/info.json

@@ -5,8 +5,6 @@
     "usb": {
         "vid": "0xCB10"
     },
-    "processor": "atmega32u4",
-    "bootloader": "atmel-dfu",
     "features": {
         "audio": false,
         "bootmagic": true,