go: update 1.19.4 -> 1.20

No longer package go-runtime-staticdev into sdk packagegroup,
as go-runtime 1.20 doesn't build the static bits anymore
(possibly can be enabled via build config, if proven necessary).

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>