`SeverityType` does not contain element with name `CVSS_V4`

When uploading a (C)OSV JSON which contains CVSS_V4, such as:

{
  "severity": [
    {
      "type": "CVSS_V4",
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
    }
  ]
}

the following exception is printed to the log:

16:10:08.813 [boundedElastic-7] ERROR c.s.cosv.backend.service.CosvService - Failed to process raw COSV file with id: 1 kotlinx.serialization.SerializationException: com.saveourtool.osv4k.SeverityType does not contain element with name 'CVSS_V4'
	at kotlinx.serialization.json.internal.JsonNamesMapKt.getJsonNameIndexOrThrow(JsonNamesMap.kt:107)
	Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Assembly trace from producer [reactor.core.publisher.MonoFlattenIterable] :
	reactor.core.publisher.Mono.flatMapIterable(Mono.java:3205)
	com.saveourtool.cosv.backend.service.CosvService$doProcess$1.invoke(CosvService.kt:192)
Error has been observed at the following site(s):
	*__Mono.flatMapIterable ⇢ at com.saveourtool.cosv.backend.service.CosvService$doProcess$1.invoke(CosvService.kt:192)
	|_         Flux.flatMap ⇢ at com.saveourtool.cosv.backend.service.CosvService$doProcess$1.invoke(CosvService.kt:193)
	|_   Flux.onErrorResume ⇢ at com.saveourtool.cosv.backend.service.CosvService$doProcess$1.invoke(CosvService.kt:194)
	|_     Flux.collectList ⇢ at com.saveourtool.cosv.backend.service.CosvService$doProcess$1.invoke(CosvService.kt:199)
	|_         Mono.flatMap ⇢ at com.saveourtool.cosv.backend.service.CosvService$doProcess$1.invoke(CosvService.kt:200)
	*_____________Mono.then ⇢ at com.saveourtool.cosv.backend.service.CosvService$doProcess$1$4.invoke(CosvService.kt:197)
Original Stack Trace:
		at kotlinx.serialization.json.internal.JsonNamesMapKt.getJsonNameIndexOrThrow(JsonNamesMap.kt:107)
		at kotlinx.serialization.json.internal.JsonNamesMapKt.getJsonNameIndexOrThrow$default(JsonNamesMap.kt:104)
		at kotlinx.serialization.json.internal.AbstractJsonTreeDecoder.decodeTaggedEnum(TreeJsonDecoder.kt:87)
		at kotlinx.serialization.json.internal.AbstractJsonTreeDecoder.decodeTaggedEnum(TreeJsonDecoder.kt:36)
		at kotlinx.serialization.internal.TaggedDecoder.decodeEnum(Tagged.kt:233)

Depends on:

• saveourtool/cosv4k#23