upsert() not working when trying to update a DateTime with a higher precision than configured

[Bassadin]

Bug description

When I tried to upsert a timestamp (example: 2023-04-02T10:13:25.915541Z) into my PostgreSQL DB (whose DateTime field uses a default precision of 3), I ran into a unique constraint that I had set for the field.
The inserting beforehand worked (when there wasn't a value there).

More info (with a slightly more bloated prisma and code example) can be found in this thread.

How to reproduce

1. See Schema and code further down.
2. The first run (create) works
3. The second run (expected: do nothing) fails. Because Prisma seems to still try to insert the value (that Postgres seemingly rounded).

Expected behavior

Expected to upsert the value as expected (maybe with a rounded value)

Prisma information

model ModelName {
    id                  Int                  @id @default(autoincrement())
    timestamp           DateTime             
    deviceId            String

    @@unique([deviceId, timestamp])
}

Code:

 await this.prisma.modelName.upsert({
    where: {
        deviceId_timestamp: {
            deviceId: "1",
            timestamp: "2023-04-02T10:13:25.915541Z",
        },
    },
    create: {
        deviceId: "1",
        timestamp: "2023-04-02T10:13:25.915541Z",
    },
    update: {},
});

Environment & setup

• OS: Windows
• Database: PostgreSQL
• Node.js version: v18.15.0

Prisma Version

4.12.0