retention is mandatory param at LogGroups

[fogfish]

Fail with error Missing required key 'retentionInDays' in params

new c3.logs.LogGroup(stack, 'MyLogs', {
  kmsKey,
  logGroupName: 'MyLogs',
  removalPolicy,
})

Ok:

new c3.logs.LogGroup(stack, 'MyLogs', {
  kmsKey,
  logGroupName: 'MyLogs',
  removalPolicy,
  retention: logs.RetentionDays.ONE_DAY,
})