feat(`sol!`): make `#[sol(rpc)]` default if `rpc` feat enabled #2269

Job	Run time
check no_std	33s
docs	55s
features stable	1m 41s
clippy	1m 1s
features stable --all-targets	24s
fmt	13s
features nightly	2m 22s
miri --no-default-features	1m 1s
features nightly --all-targets	45s
miri	1m 4s
miri --all-features	1m 6s
test ubuntu-latest stable --no-default-features	35s
wasm	29s
test ubuntu-latest stable	37s
test ubuntu-latest nightly --no-default-features	56s
test ubuntu-latest nightly	53s
test ubuntu-latest 1.81 --no-default-features	29s
test ubuntu-latest 1.81	34s
test windows-latest stable --no-default-features	2m 11s
test windows-latest stable	2m 2s
test windows-latest nightly --no-default-features	2m 7s
test windows-latest nightly	2m 15s
test windows-latest 1.81 --no-default-features	1m 11s
test windows-latest 1.81	1m 14s
test ubuntu-latest 1.81 --features json	33s
test windows-latest 1.81 --features json	1m 25s
test ubuntu-latest nightly --all-features	56s
test windows-latest nightly --all-features	2m 29s
deny / cargo deny check	17s
ci success	2s
	32m 20s

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