[Feature Request] Provide a much more up-to-date compiler (at least GCC 12)

This core (as well as many other Arduino cores) ships with GCC `7.2.1 20170904`.

```bash
~/.arduino15/packages/arduino/tools/arm-none-eabi-gcc/7-2017q4/bin/arm-none-eabi-g++ --version
arm-none-eabi-g++ (GNU Tools for Arm Embedded Processors 7-2017-q4-major) 7.2.1 20170904 (release) [ARM/embedded-7-branch revision 255204]
```

Meanwhile `arduino-pico` uses GCC 12 and [stm32duino](https://github.com/stm32duino/Arduino_Core_STM32) uses GCC 10 (at least).

I suggest updating tooling to GCC 12.

Start by locating where ArduinoCore-renesas selects the arm-none-eabi-gcc 7-2017q4 toolchain shown in the issue, then review how comparable Arduino cores provide newer compiler versions. Done means the core uses a GCC 12-era toolchain and its builds still complete successfully.

Written by the indexing model from the issue text.