Rq-exporter

Pass the password when connecting to the Sentinel master.

Pass the password when creating the Sentinel connection.

- Added support for Sentinel hosts with different ports (`sentinel1:26379,sentinel2:26380`)
- Changed Python Docker image to `3.8-slim-bookworm`

New metrics for successful and failed job counts and worker total working time in seconds, used to calculate the avg. job latency, added by mkotsalainen.

| Metric Name | Type | Labels | Description |
| ------------------------------- | ------- | ------------------------- | --------------------------------------- |
| `rq_workers_success_total` | Counter | `name`, `queues` | Successful job count by worker |
| `rq_workers_failed_total` | Counter | `name`, `queues` | Failed job count by worker |
| `rq_workers_working_time_total` | Counter | `name`, `queues` | Total working time in seconds by worker |

Build a new Docker image.

Use explicit UID (`999`) for the container user. Thanks to aleksandr-vin