`NumberFormatException` at `AbstractS3KeyDatabaseManager<*, *, *>.asS3KeyValidator()` (`BackupStorageUtils.kt`)

[0x6675636b796f75676974687562]

Reproduced locally with a non-empty database (50k vulnerabilities loaded):

20:55:50.889 [s3-operations-cnb-10] ERROR reactor.core.publisher.Operators - Operator called default onErrorDropped reactor.core.Exceptions$ErrorCallbackNotImplemented: java.lang.NumberFormatException: For input string: ""
Caused by: java.lang.NumberFormatException: For input string: ""
	at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:67)
	at java.base/java.lang.Long.parseLong(Long.java:721)
	at java.base/java.lang.Long.parseLong(Long.java:836)
	at com.saveourtool.common.storage.BackupStorageUtilsKt$asS3KeyValidator$1.invoke(BackupStorageUtils.kt:99)
	at com.saveourtool.common.storage.BackupStorageUtilsKt$asS3KeyValidator$1.invoke(BackupStorageUtils.kt:98)

21:00:40.042 [parallel-1] WARN c.s.cosv.backend.service.CosvService - Storage RawCosvFileStorage and repository CosvRepository are not initialized in 5m 

The issue is caused by the key being the same as the prefix (cnb/files/cosv/).