Add test to beacon node fallback feature #19114

Job	Run time
check-msrv	5m 25s
Check for 'skip-ci' label	1s
check-code	5m 20s
lockbud	14m 26s
target-branch-check	1s
basic-simulator-ubuntu	21m 28s
cli-check	14m 21s
cargo-udeps	7m 10s
beacon-chain-tests	16m 53s
compile-with-beta-compiler	13m 41s
debug-tests-ubuntu	3m 3s
ef-tests-ubuntu	6m 1s
execution-engine-integration-ubuntu	11m 1s
fallback-simulator-ubuntu	18m 40s
network-tests	25m 10s
op-pool-tests	22m 32s
release-tests-ubuntu	3m 40s
release-tests-windows	9m 56s
slasher-tests	3m 32s
state-transition-vectors-ubuntu	9m 19s
test-suite-success	0s
	3h 31m 40s

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