Detect invalid proposer signature on RPC block processing #18965

Job	Run time
Check for 'skip-ci' label	1s
check-code	9m 7s
check-msrv	5m 51s
lockbud	13m 59s
target-branch-check	1s
cli-check	13m 29s
beacon-chain-tests	6m 47s
cargo-udeps	7m 23s
basic-simulator-ubuntu	21m 7s
compile-with-beta-compiler	13m 35s
debug-tests-ubuntu	7m 32s
ef-tests-ubuntu	12m 40s
execution-engine-integration-ubuntu	7m 18s
fallback-simulator-ubuntu	18m 50s
network-tests	27m 3s
op-pool-tests	22m 26s
release-tests-ubuntu	20m 29s
release-tests-windows	34m 13s
slasher-tests	3m 46s
state-transition-vectors-ubuntu	9m 2s
test-suite-success	0s
	4h 14m 39s

Provide feedback