Update checkout and codecov actions to v4 #321

Job	Run time
Pharo64-10 + app-config	50s
Pharo64-10 + app-control	48s
Pharo64-10 + app-info	32s
Pharo64-10 + core	35s
Pharo64-10 + dependent-sunit-extensions	38s
Pharo64-10 + deployment	41s
Pharo64-10 + development	41s
Pharo64-10 + examples	43s
Pharo64-10 + healthcheck	37s
Pharo64-10 + json-rpc	33s
Pharo64-10 + loggers	41s
Pharo64-10 + metrics	37s
Pharo64-10 + metrics-http	36s
Pharo64-10 + tests	52s
Pharo64-10 + tools	32s
Pharo64-11 + app-config	41s
Pharo64-11 + app-control	39s
Pharo64-11 + app-info	31s
Pharo64-11 + core	40s
Pharo64-11 + dependent-sunit-extensions	31s
Pharo64-11 + deployment	50s
Pharo64-11 + development	43s
Pharo64-11 + examples	35s
Pharo64-11 + healthcheck	29s
Pharo64-11 + json-rpc	41s
Pharo64-11 + loggers	31s
Pharo64-11 + metrics	33s
Pharo64-11 + metrics-http	34s
Pharo64-11 + tests	41s
Pharo64-11 + tools	21s
	18m 56s

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