v1.1.7 or later fails when building images in parallel

#### Overview of the Issue

Ever since v1.1.7, some of our windows builds have been failing with the error

"Error creating windows password: time out while waiting for the password to be created"

On a hunch, instead of having packer use oslogin to create the packer user we created the packer user in a startup script. We then started getting the error

"errored after 12 seconds 726 milliseconds: Error importing SSH public key for OSLogin: googleapi: Error 409: Multiple concurrent mutations were attempted. Please retry the request."

Reverting back to v1.1.6 of the plugin avoids all these errors.

#### Reproduction Steps

Run this template provided

### Plugin and Packer version

1.12.0 or later

### Simplified Packer Buildfile

```
packer {
required_plugins {
googlecompute = {
source = "github.com/hashicorp/googlecompute"
version = "~> 1.0"
}
}
}

source "googlecompute" "windows" {
project_id = var.project_id
ssh_username = "packer"
zone = "us-central1-a"
subnetwork = var.subnetwork
network_project_id = var.project_id
use_internal_ip = true
enable_secure_boot = true
omit_external_ip = true
use_iap = false

image_labels = {}

disk_size = 50
machine_type = "n2d-standard-2"
tags = ["packer", "allow-internet-egress"]

metadata = {
windows-startup-script-cmd = <