Using `forUpdate` in suspended transaction causes deadlock

Reproducer:

```
fun main(args: Array) {
Database.connect(
"jdbc:postgresql://localhost:54321/grazie",
user = "admin",
password = "admin",
driver = "org.postgresql.Driver"
)
while (true) {
try {
runBlocking {
repeat(2) {
launch {
newSuspendedTransaction {
val license = UserLicenseEntity.find { UserLicenseTable.id eq 1 }.forUpdate().singleOrNull()
println(license?.licenseType ?: "No license found")
delay(50)
}
}
}
}
} catch (e: Exception) {
}
}
}

class UserLicenseEntity(id: EntityID) : IntEntity(id) {
val licenseType by UserLicenseTable.license_type

companion object : IntEntityClass(UserLicenseTable)
}

object UserLicenseTable : IntIdTable("user_license") {
val license_type = text("license_type")
}
```

If I am not missing something, it should run endless and print licenseType. Instead, licenseType is printed once and then the program hangs