Add v4.2.0 to changelog #1380

Job	Run time
static-analysis (8.3, cs)	24s
static-analysis (8.3, stan)	49s
static-analysis (8.3, swagger:validate)	13s
api-tests / tests (8.2)	1m 2s
cli-tests / tests (8.2)	37s
api-tests / tests (8.3)	1m 16s
unit-tests / tests (8.2)	21s
cli-tests / tests (8.3)	36s
api-tests / tests (8.4)	1m 5s
unit-tests / tests (8.3)	29s
cli-tests / tests (8.4)	23s
unit-tests / tests (8.4)	29s
db-tests (ms) / db-tests (8.2)	46s
db-tests (mysql) / db-tests (8.2)	39s
db-tests (maria) / db-tests (8.2)	35s
db-tests (maria) / db-tests (8.3)	29s
db-tests (mysql) / db-tests (8.3)	31s
db-tests (ms) / db-tests (8.3)	53s
db-tests (mysql) / db-tests (8.4)	40s
db-tests (maria) / db-tests (8.4)	24s
db-tests (ms) / db-tests (8.4)	56s
db-tests (postgres) / db-tests (8.2)	24s
db-tests (postgres) / db-tests (8.3)	25s
db-tests (sqlite:ci) / db-tests (8.2)	28s
db-tests (postgres) / db-tests (8.4)	33s
db-tests (sqlite:ci) / db-tests (8.3)	17s
db-tests (sqlite:ci) / db-tests (8.4)	29s
upload-coverage (8.3)	14s
delete-artifacts	1s
	16m 28s

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