Add test to beacon node fallback feature #19450

Job	Run time
target-branch-check	1s
Check for 'skip-ci' label	1s
check-code	5m 30s
check-msrv	5m 17s
lockbud	5m 21s
beacon-chain-tests	5m 25s
release-tests-windows	5m 17s
network-tests	5m 58s
debug-tests-ubuntu	5m 25s
op-pool-tests	5m 23s
release-tests-ubuntu	5m 27s
slasher-tests	1m 37s
state-transition-vectors-ubuntu	2m 23s
basic-simulator-ubuntu	5m 23s
cargo-sort	16s
cargo-udeps	5m 21s
cli-check	5m 22s
compile-with-beta-compiler	5m 21s
ef-tests-ubuntu	5m 24s
execution-engine-integration-ubuntu	5m 26s
fallback-simulator-ubuntu	5m 56s
test-suite-success	1s
	1h 31m 35s

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