chore: Run flakey e2e tests on CI but allow failure #5314

Job	Run time
setup / start-builder	6s
setup / setup	20s
build	22m 10s
yarn-project-formatting	20m 30s
bb-native-tests	7m 34s
yarn-project-test	21m 16s
bb-bench-binaries	8m 56s
setup-bench / start-builder	1m 6s
setup-bench / setup	24s
bb-bench	5m 7s
e2e (e2e-browser)	1m 28s
e2e (e2e-docs-examples)	59s
e2e (e2e-sandbox-example)	1m 31s
e2e (e2e-tests)	9m 57s
e2e (flakey-e2e-tests)	4m 33s
e2e (guides-dapp-testing)	2m 53s
e2e (guides-writing-an-account-contract)	1m 0s
e2e (integration-l1-publisher)	1m 58s
e2e (pxe)	39s
e2e (uniswap-trade-on-l1-from-l2)	5m 39s
merge-check	1s
notify	0s
	1h 58m 7s

Provide feedback