Update framework-gap_sdk

[maxgerhardt]

Per https://community.platformio.org/t/update-gap-sdk-riscv-gap/20464.

Is there a way to update the GAP SDK toolchain used by Platformio? Latest version of GAP SDK is 3.9.1 while the one used by Platformio for the Gapuino board is 2.0.0.

Current version is

platform-riscv_gap/platform.json

Lines 39 to 42 in af6603a

	"framework-gap_sdk": {
	"type": "framework",
	"version": "~2.0.0"
	},

But latest in https://github.com/GreenWaves-Technologies/gap_sdk is 3.9.1.