Migration of Gitlab lint, check, workspace, examples stages to GitHub Actions #12

Job	Run time
set-image	3s
clippy	12m 47s
clippy-examples (STD)	11m 52s
dylint	4m 48s
check (STD)	10m 21s
check (WASM)	1m 46s
fmt	3m 1s
spellcheck	1m 56s
check (RISCV)	1m 46s
clippy-examples (WASM)	3m 43s
test	13m 24s
build (STD)	17m 59s
build (WASM)	2m 42s
examples-test	17m 36s
docs	11m 28s
codecov	28m 32s
examples-docs	4m 14s
examples-contract-build (WASM)	30m 0s
examples-contract-build (RISCV)	3m 48s
	3h 1m 46s

Provide feedback