feat: Add Cloud Run Jobs support as queue target

[robertpcontreras-ts]

Summary

This PR adds support for processing Laravel queue jobs using Google Cloud Run Jobs as a target type. Instead of dispatching jobs to an HTTP endpoint, Cloud Tasks triggers a Cloud Run Job execution via the Cloud Run Jobs API, which runs an Artisan command to process the job.

Features

• New Artisan command: cloud-tasks:work-job - Processes jobs via Cloud Run Jobs container execution
• Cloud Run Jobs API integration: Cloud Tasks dispatches to run.googleapis.com/v2/.../jobs/{job}:run
• Environment variable passing: Job payload and task name passed via containerOverrides.env
• Large payload storage: Payloads exceeding a configurable threshold are stored in Laravel Filesystem (GCS, S3, etc.) and retrieved by the worker
• OAuth authentication: Uses OAuth token with cloud-platform scope for Cloud Run Jobs API

Configuration

'cloudtasks' => [
    // ... existing config
    'cloud_run_job' => env('CLOUD_TASKS_USE_CLOUD_RUN_JOB', false),
    'cloud_run_job_name' => env('CLOUD_RUN_JOB_NAME'),
    'cloud_run_job_region' => env('CLOUD_RUN_JOB_REGION'),
    
    // Optional: Large payload storage
    'payload_disk' => env('CLOUD_TASKS_PAYLOAD_DISK'),
    'payload_prefix' => env('CLOUD_TASKS_PAYLOAD_PREFIX', 'cloud-tasks-payloads'),
    'payload_threshold' => env('CLOUD_TASKS_PAYLOAD_THRESHOLD', 10240),
],

Breaking Changes

None. This is an additive feature - the cloud_run_job option defaults to false, preserving existing behaviour.

Tests

• 23 new tests covering Cloud Run Job dispatch and worker functionality
• All existing tests continue to pass (95 unit tests, 146 assertions)

Documentation

• Added Cloud Run Jobs usage guide
• Added IAM permissions documentation with gcloud commands

[marickvantuil]

This is really nice, thanks! I will review everything later.